1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
|
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>API — pygrib documentation</title>
<link rel="stylesheet" href="_static/pygments.css" type="text/css" />
<link rel="stylesheet" href="_static/nature.css" type="text/css" />
<link rel="stylesheet" type="text/css" href="_static/css/nature2.css" />
<script id="documentation_options" data-url_root="./" src="_static/documentation_options.js"></script>
<script src="_static/jquery.js"></script>
<script src="_static/underscore.js"></script>
<script src="_static/doctools.js"></script>
<script src="_static/language_data.js"></script>
<link rel="index" title="Index" href="genindex.html" />
<link rel="search" title="Search" href="search.html" />
<link rel="prev" title="Installation" href="installing.html" />
</head><body>
<div class="related" role="navigation" aria-label="related navigation">
<h3>Navigation</h3>
<ul>
<li class="right" style="margin-right: 10px">
<a href="genindex.html" title="General Index"
accesskey="I">index</a></li>
<li class="right" >
<a href="py-modindex.html" title="Python Module Index"
>modules</a> |</li>
<li class="right" >
<a href="installing.html" title="Installation"
accesskey="P">previous</a> |</li>
<li class="nav-item nav-item-0"><a href="index.html">pygrib documentation</a> »</li>
<li class="nav-item nav-item-this"><a href="">API</a></li>
</ul>
</div>
<div class="document">
<div class="documentwrapper">
<div class="bodywrapper">
<div class="body" role="main">
<div class="section" id="api">
<h1>API<a class="headerlink" href="#api" title="Permalink to this headline">¶</a></h1>
<div class="section" id="example-usage">
<h2>Example usage<a class="headerlink" href="#example-usage" title="Permalink to this headline">¶</a></h2>
<p>from the python interpreter prompt, import the package:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">pygrib</span>
</pre></div>
</div>
<p>open a GRIB file, create a grib message iterator:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">grbs</span> <span class="o">=</span> <span class="n">pygrib</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="s1">'sampledata/flux.grb'</span><span class="p">)</span>
</pre></div>
</div>
<p>pygrib open instances behave like regular python file objects, with
<code class="docutils literal notranslate"><span class="pre">seek</span></code>, <code class="docutils literal notranslate"><span class="pre">tell</span></code>, <code class="docutils literal notranslate"><span class="pre">read</span></code>, <code class="docutils literal notranslate"><span class="pre">readline</span></code> and <code class="docutils literal notranslate"><span class="pre">close</span></code> methods, except
that offsets are measured in grib messages instead of bytes:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">grbs</span><span class="o">.</span><span class="n">seek</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">grbs</span><span class="o">.</span><span class="n">tell</span><span class="p">()</span>
<span class="go">2</span>
<span class="gp">>>> </span><span class="n">grb</span> <span class="o">=</span> <span class="n">grbs</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="mi">1</span><span class="p">)[</span><span class="mi">0</span><span class="p">]</span> <span class="c1"># read returns a list with the next N (N=1 in this case) messages.</span>
<span class="gp">>>> </span><span class="n">grb</span> <span class="c1"># printing a grib message object displays summary info</span>
<span class="go">3:Maximum temperature:K (instant):regular_gg:heightAboveGround:level 2 m:fcst time 108-120 hrs:from 200402291200</span>
<span class="gp">>>> </span><span class="n">grbs</span><span class="o">.</span><span class="n">tell</span><span class="p">()</span>
<span class="go">3</span>
</pre></div>
</div>
<p>print an inventory of the file:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">grbs</span><span class="o">.</span><span class="n">seek</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
<span class="gp">>>> </span><span class="k">for</span> <span class="n">grb</span> <span class="ow">in</span> <span class="n">grbs</span><span class="p">:</span>
<span class="gp">>>> </span> <span class="n">grb</span>
<span class="go">1:Precipitation rate:kg m**-2 s**-1 (avg):regular_gg:surface:level 0:fcst time 108-120 hrs (avg):from 200402291200</span>
<span class="go">2:Surface pressure:Pa (instant):regular_gg:surface:level 0:fcst time 120 hrs:from 200402291200</span>
<span class="go">3:Maximum temperature:K (instant):regular_gg:heightAboveGround:level 2 m:fcst time 108-120 hrs:from 200402291200</span>
<span class="go">4:Minimum temperature:K (instant):regular_gg:heightAboveGround:level 2 m:fcst time 108-120 hrs:from 200402291200</span>
</pre></div>
</div>
<p>find the first grib message with a matching name:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">grb</span> <span class="o">=</span> <span class="n">grbs</span><span class="o">.</span><span class="n">select</span><span class="p">(</span><span class="n">name</span><span class="o">=</span><span class="s1">'Maximum temperature'</span><span class="p">)[</span><span class="mi">0</span><span class="p">]</span>
</pre></div>
</div>
<p>extract the data values using the <code class="docutils literal notranslate"><span class="pre">values</span></code> key (<code class="docutils literal notranslate"><span class="pre">grb.keys()</span></code> will return a list of the available keys):</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">maxt</span> <span class="o">=</span> <span class="n">grb</span><span class="o">.</span><span class="n">values</span> <span class="c1"># same as grb['values']</span>
<span class="go"># The data is returned as a numpy array, or if missing values or a bitmap</span>
<span class="go"># are present, a numpy masked array. Reduced lat/lon or gaussian grid</span>
<span class="go"># data is automatically expanded to a regular grid. Details of the internal</span>
<span class="go"># representation of the grib data (such as the scanning mode) are handled</span>
<span class="go"># automatically.</span>
<span class="gp">>>> </span><span class="n">maxt</span><span class="o">.</span><span class="n">shape</span><span class="p">,</span> <span class="n">maxt</span><span class="o">.</span><span class="n">min</span><span class="p">(),</span> <span class="n">maxt</span><span class="o">.</span><span class="n">max</span><span class="p">()</span>
<span class="go">(94, 192) 223.7 319.9</span>
</pre></div>
</div>
<p>get the latitudes and longitudes of the grid:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">lats</span><span class="p">,</span> <span class="n">lons</span> <span class="o">=</span> <span class="n">grb</span><span class="o">.</span><span class="n">latlons</span><span class="p">()</span>
<span class="gp">>>> </span><span class="n">lats</span><span class="o">.</span><span class="n">shape</span><span class="p">,</span> <span class="n">lats</span><span class="o">.</span><span class="n">min</span><span class="p">(),</span> <span class="n">lats</span><span class="o">.</span><span class="n">max</span><span class="p">(),</span> <span class="n">lons</span><span class="o">.</span><span class="n">shape</span><span class="p">,</span> <span class="n">lons</span><span class="o">.</span><span class="n">min</span><span class="p">(),</span> <span class="n">lons</span><span class="o">.</span><span class="n">max</span><span class="p">()</span>
<span class="go">(94, 192) -88.5419501373 88.5419501373 0.0 358.125</span>
</pre></div>
</div>
<p>get the second grib message:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">grb</span> <span class="o">=</span> <span class="n">grbs</span><span class="o">.</span><span class="n">message</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span> <span class="c1"># same as grbs.seek(1); grb=grbs.readline()</span>
<span class="gp">>>> </span><span class="n">grb</span>
<span class="go">2:Surface pressure:Pa (instant):regular_gg:surface:level 0:fcst time 120 hrs:from 200402291200</span>
</pre></div>
</div>
<p>extract data and get lat/lon values for a subset over North America:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">data</span><span class="p">,</span> <span class="n">lats</span><span class="p">,</span> <span class="n">lons</span> <span class="o">=</span> <span class="n">grb</span><span class="o">.</span><span class="n">data</span><span class="p">(</span><span class="n">lat1</span><span class="o">=</span><span class="mi">20</span><span class="p">,</span><span class="n">lat2</span><span class="o">=</span><span class="mi">70</span><span class="p">,</span><span class="n">lon1</span><span class="o">=</span><span class="mi">220</span><span class="p">,</span><span class="n">lon2</span><span class="o">=</span><span class="mi">320</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">data</span><span class="o">.</span><span class="n">shape</span><span class="p">,</span> <span class="n">lats</span><span class="o">.</span><span class="n">min</span><span class="p">(),</span> <span class="n">lats</span><span class="o">.</span><span class="n">max</span><span class="p">(),</span> <span class="n">lons</span><span class="o">.</span><span class="n">min</span><span class="p">(),</span> <span class="n">lons</span><span class="o">.</span><span class="n">max</span><span class="p">()</span>
<span class="go">(26, 53) 21.904439458 69.5216630593 221.25 318.75</span>
</pre></div>
</div>
<p>modify the values associated with existing keys:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">grb</span><span class="p">[</span><span class="s1">'forecastTime'</span><span class="p">]</span> <span class="o">=</span> <span class="mi">240</span>
<span class="gp">>>> </span><span class="n">grb</span><span class="o">.</span><span class="n">dataDate</span> <span class="o">=</span> <span class="mi">20100101</span>
</pre></div>
</div>
<p>get the binary string associated with the coded message:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">msg</span> <span class="o">=</span> <span class="n">grb</span><span class="o">.</span><span class="n">tostring</span><span class="p">()</span>
<span class="gp">>>> </span><span class="n">grbs</span><span class="o">.</span><span class="n">close</span><span class="p">()</span> <span class="c1"># close the grib file.</span>
</pre></div>
</div>
<p>write the modified message to a new GRIB file:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">grbout</span> <span class="o">=</span> <span class="nb">open</span><span class="p">(</span><span class="s1">'test.grb'</span><span class="p">,</span><span class="s1">'wb'</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">grbout</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">msg</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">grbout</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>
<span class="gp">>>> </span><span class="n">pygrib</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="s1">'test.grb'</span><span class="p">)</span><span class="o">.</span><span class="n">readline</span><span class="p">()</span>
<span class="go">1:Surface pressure:Pa (instant):regular_gg:surface:level 0:fcst time 240 hrs:from 201001011200</span>
</pre></div>
</div>
</div>
<div class="section" id="module-pygrib">
<span id="module-docstrings"></span><h2>Module docstrings<a class="headerlink" href="#module-pygrib" title="Permalink to this headline">¶</a></h2>
<p>pygrib module</p>
<dl class="py function">
<dt id="pygrib.fromstring">
<code class="sig-prename descclassname">pygrib.</code><code class="sig-name descname">fromstring</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">string</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.fromstring" title="Permalink to this definition">¶</a></dt>
<dd><p>Create a <a class="reference internal" href="#pygrib.gribmessage" title="pygrib.gribmessage"><code class="xref py py-class docutils literal notranslate"><span class="pre">gribmessage</span></code></a> instance from a python bytes object
representing a binary grib message (the reverse of <a class="reference internal" href="#pygrib.gribmessage.tostring" title="pygrib.gribmessage.tostring"><code class="xref py py-meth docutils literal notranslate"><span class="pre">gribmessage.tostring()</span></code></a>).</p>
</dd></dl>
<dl class="py function">
<dt id="pygrib.gaulats">
<code class="sig-prename descclassname">pygrib.</code><code class="sig-name descname">gaulats</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">nlats</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.gaulats" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns nlats gaussian latitudes, in degrees, oriented from
north to south. nlats must be even.</p>
</dd></dl>
<dl class="py class">
<dt id="pygrib.gribmessage">
<em class="property">class </em><code class="sig-prename descclassname">pygrib.</code><code class="sig-name descname">gribmessage</code><a class="headerlink" href="#pygrib.gribmessage" title="Permalink to this definition">¶</a></dt>
<dd><p>Bases: <a class="reference external" href="https://docs.python.org/3/library/functions.html#object" title="(in Python v3.9)"><code class="xref py py-class docutils literal notranslate"><span class="pre">object</span></code></a></p>
<p>Grib message object.</p>
<p>Each grib message has attributes corresponding to GRIB
<a class="reference external" href="https://confluence.ecmwf.int/display/ECC/GRIB+Keys">keys</a>.
Parameter names are described by the <code class="docutils literal notranslate"><span class="pre">name</span></code>, <code class="docutils literal notranslate"><span class="pre">shortName</span></code> and <code class="docutils literal notranslate"><span class="pre">paramID</span></code> keys.
pygrib also defines some special attributes which are defined below</p>
<dl class="field-list simple">
<dt class="field-odd">Variables</dt>
<dd class="field-odd"><ul class="simple">
<li><p><strong>messagenumber</strong> – The grib message number in the file.</p></li>
<li><p><strong>projparams</strong> – A dictionary containing proj4 key/value pairs describing
the grid. Set to <code class="docutils literal notranslate"><span class="pre">None</span></code> for unsupported grid types.</p></li>
<li><p><strong>expand_reduced</strong> – If True (default), reduced lat/lon and gaussian grids
will be expanded to regular grids when data is accessed via <code class="docutils literal notranslate"><span class="pre">values</span></code> key. If
False, data is kept on unstructured reduced grid, and is returned in a 1-d
array.</p></li>
<li><p><strong>fcstimeunits</strong> – A string representing the forecast time units
(an empty string if not defined).</p></li>
<li><p><strong>analDate</strong> – A python datetime instance describing the analysis date
and time for the forecast. Only set if forecastTime and julianDay keys
exist.</p></li>
<li><p><strong>validDate</strong> – A python datetime instance describing the valid date
and time for the forecast. Only set if forecastTime and julianDay keys
exist, and fcstimeunits is defined. If forecast time
is a range, then <code class="docutils literal notranslate"><span class="pre">validDate</span></code> corresponds to the end of the range.</p></li>
</ul>
</dd>
</dl>
<dl class="py method">
<dt id="pygrib.gribmessage.data">
<code class="sig-name descname">data</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">lat1</span><span class="o">=</span><span class="default_value">None</span></em>, <em class="sig-param"><span class="n">lat2</span><span class="o">=</span><span class="default_value">None</span></em>, <em class="sig-param"><span class="n">lon1</span><span class="o">=</span><span class="default_value">None</span></em>, <em class="sig-param"><span class="n">lon2</span><span class="o">=</span><span class="default_value">None</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.gribmessage.data" title="Permalink to this definition">¶</a></dt>
<dd><p>extract data, lats and lons for a subset region defined
by the keywords lat1,lat2,lon1,lon2.</p>
<p>The default values of lat1,lat2,lon1,lon2 are None, which
means the entire grid is returned.</p>
<p>If the grid type is unprojected lat/lon and a geographic
subset is requested (by using the lat1,lat2,lon1,lon2 keywords),
then 2-d arrays are returned, otherwise 1-d arrays are returned.</p>
</dd></dl>
<dl class="py method">
<dt id="pygrib.gribmessage.expand_grid">
<code class="sig-name descname">expand_grid</code><span class="sig-paren">(</span><em class="sig-param">True or False</em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.gribmessage.expand_grid" title="Permalink to this definition">¶</a></dt>
<dd><p>toggle expansion of 1D reduced grid data to a regular (2D) grid (on
by default).</p>
</dd></dl>
<dl class="py method">
<dt id="pygrib.gribmessage.has_key">
<code class="sig-name descname">has_key</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">key</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.gribmessage.has_key" title="Permalink to this definition">¶</a></dt>
<dd><p>tests whether a grib message object has a specified key.</p>
</dd></dl>
<dl class="py method">
<dt id="pygrib.gribmessage.is_missing">
<code class="sig-name descname">is_missing</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">key</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.gribmessage.is_missing" title="Permalink to this definition">¶</a></dt>
<dd><p>returns True if key is invalid or value associated with key is equal
to grib missing value flag (False otherwise)</p>
</dd></dl>
<dl class="py method">
<dt id="pygrib.gribmessage.keys">
<code class="sig-name descname">keys</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.gribmessage.keys" title="Permalink to this definition">¶</a></dt>
<dd><p>return keys associated with a grib message in a list</p>
</dd></dl>
<dl class="py method">
<dt id="pygrib.gribmessage.latlons">
<code class="sig-name descname">latlons</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.gribmessage.latlons" title="Permalink to this definition">¶</a></dt>
<dd><p>compute lats and lons (in degrees) of grid.
Currently handles regular lat/lon, global gaussian, mercator, stereographic,
lambert conformal, albers equal-area, space-view, azimuthal
equidistant, reduced gaussian, reduced lat/lon,
lambert azimuthal equal-area, rotated lat/lon and rotated gaussian grids.</p>
<dl class="field-list simple">
<dt class="field-odd">Returns</dt>
<dd class="field-odd"><p><code class="docutils literal notranslate"><span class="pre">lats,lons</span></code> numpy arrays
containing latitudes and longitudes of grid (in degrees).</p>
</dd>
</dl>
</dd></dl>
<dl class="py method">
<dt id="pygrib.gribmessage.tostring">
<code class="sig-name descname">tostring</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.gribmessage.tostring" title="Permalink to this definition">¶</a></dt>
<dd><p>return coded grib message in a binary string.</p>
</dd></dl>
<dl class="py method">
<dt id="pygrib.gribmessage.valid_key">
<code class="sig-name descname">valid_key</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">key</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.gribmessage.valid_key" title="Permalink to this definition">¶</a></dt>
<dd><p>tests whether a grib message object has a specified key,
it is not missing and it has a value that can be read.</p>
</dd></dl>
</dd></dl>
<dl class="py class">
<dt id="pygrib.index">
<em class="property">class </em><code class="sig-prename descclassname">pygrib.</code><code class="sig-name descname">index</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">filename</span></em>, <em class="sig-param"><span class="o">*</span><span class="n">args</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.index" title="Permalink to this definition">¶</a></dt>
<dd><p>Bases: <a class="reference external" href="https://docs.python.org/3/library/functions.html#object" title="(in Python v3.9)"><code class="xref py py-class docutils literal notranslate"><span class="pre">object</span></code></a></p>
<p>returns grib index object given GRIB filename indexed by keys given in
<a href="#id1"><span class="problematic" id="id2">*</span></a>args. The <a class="reference internal" href="#pygrib.index.select" title="pygrib.index.select"><code class="xref py py-class docutils literal notranslate"><span class="pre">select</span></code></a> or <code class="docutils literal notranslate"><span class="pre">__call__</span></code> method can then be used to selected grib messages
based on specified values of indexed keys.
Unlike <a class="reference internal" href="#pygrib.open.select" title="pygrib.open.select"><code class="xref py py-meth docutils literal notranslate"><span class="pre">open.select()</span></code></a>, containers or callables cannot be used to
select multiple key values.
However, using <a class="reference internal" href="#pygrib.index.select" title="pygrib.index.select"><code class="xref py py-meth docutils literal notranslate"><span class="pre">index.select()</span></code></a> is much faster than <a class="reference internal" href="#pygrib.open.select" title="pygrib.open.select"><code class="xref py py-meth docutils literal notranslate"><span class="pre">open.select()</span></code></a>.</p>
<p><strong>Warning</strong>: Searching for data within multi-field grib messages does not
work using an index and is not supported by ECCODES library. NCEP
often puts u and v winds together in a single multi-field grib message. You
will get incorrect results if you try to use an index to find data in these
messages. Use the slower, but more robust <a class="reference internal" href="#pygrib.open.select" title="pygrib.open.select"><code class="xref py py-meth docutils literal notranslate"><span class="pre">open.select()</span></code></a> in this case.</p>
<p>If no key are given (i.e. <a href="#id3"><span class="problematic" id="id4">*</span></a>args is empty), it is assumed the filename represents a previously
saved index (created using the <code class="docutils literal notranslate"><span class="pre">grib_index_build</span></code> tool or <a class="reference internal" href="#pygrib.index.write" title="pygrib.index.write"><code class="xref py py-meth docutils literal notranslate"><span class="pre">index.write()</span></code></a>) instead of a GRIB file.</p>
<p>Example usage:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">pygrib</span>
<span class="gp">>>> </span><span class="n">grbindx</span><span class="o">=</span><span class="n">pygrib</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="s1">'sampledata/gfs.grb'</span><span class="p">,</span><span class="s1">'shortName'</span><span class="p">,</span><span class="s1">'typeOfLevel'</span><span class="p">,</span><span class="s1">'level'</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">grbindx</span><span class="o">.</span><span class="n">keys</span>
<span class="go">['shortName', 'level']</span>
<span class="gp">>>> </span><span class="n">selected_grbs</span><span class="o">=</span><span class="n">grbindx</span><span class="o">.</span><span class="n">select</span><span class="p">(</span><span class="n">shortName</span><span class="o">=</span><span class="s1">'gh'</span><span class="p">,</span><span class="n">typeOfLevel</span><span class="o">=</span><span class="s1">'isobaricInhPa'</span><span class="p">,</span><span class="n">level</span><span class="o">=</span><span class="mi">500</span><span class="p">)</span>
<span class="gp">>>> </span><span class="k">for</span> <span class="n">grb</span> <span class="ow">in</span> <span class="n">selected_grbs</span><span class="p">:</span>
<span class="gp">>>> </span> <span class="n">grb</span>
<span class="go">1:Geopotential height:gpm (instant):regular_ll:isobaricInhPa:level 500 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
<span class="gp">>>> </span><span class="c1"># __call__ method does same thing as select</span>
<span class="gp">>>> </span><span class="n">selected_grbs</span><span class="o">=</span><span class="n">grbindx</span><span class="p">(</span><span class="n">shortName</span><span class="o">=</span><span class="s1">'u'</span><span class="p">,</span><span class="n">typeOfLevel</span><span class="o">=</span><span class="s1">'isobaricInhPa'</span><span class="p">,</span><span class="n">level</span><span class="o">=</span><span class="mi">250</span><span class="p">)</span>
<span class="gp">>>> </span><span class="k">for</span> <span class="n">grb</span> <span class="ow">in</span> <span class="n">selected_grbs</span><span class="p">:</span>
<span class="gp">>>> </span> <span class="n">grb</span>
<span class="go">1:u-component of wind:m s**-1 (instant):regular_ll:isobaricInhPa:level 250 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
<span class="gp">>>> </span><span class="n">grbindx</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="s1">'gfs.grb.idx'</span><span class="p">)</span> <span class="c1"># save index to a file</span>
<span class="gp">>>> </span><span class="n">grbindx</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>
<span class="gp">>>> </span><span class="n">grbindx</span> <span class="o">=</span> <span class="n">pygrib</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="s1">'gfs.grb.idx'</span><span class="p">)</span> <span class="c1"># re-open index (no keys specified)</span>
<span class="gp">>>> </span><span class="n">grbindx</span><span class="o">.</span><span class="n">keys</span> <span class="c1"># not set when opening a saved index file.</span>
<span class="go">None</span>
<span class="gp">>>> </span><span class="k">for</span> <span class="n">grb</span> <span class="ow">in</span> <span class="n">selected_grbs</span><span class="p">:</span>
<span class="gp">>>> </span> <span class="n">grb</span>
<span class="go">1:u-component of wind:m s**-1 (instant):regular_ll:isobaricInhPa:level 250 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
</pre></div>
</div>
<dl class="field-list simple">
<dt class="field-odd">Variables</dt>
<dd class="field-odd"><ul class="simple">
<li><p><a class="reference internal" href="#pygrib.gribmessage.keys" title="pygrib.gribmessage.keys"><strong>keys</strong></a> – list of strings containing keys used in the index. Set to <code class="docutils literal notranslate"><span class="pre">None</span></code>
when opening a previously saved grib index file.</p></li>
<li><p><a class="reference external" href="https://docs.python.org/3/library/types.html#module-types" title="(in Python v3.9)"><strong>types</strong></a> – if keys are typed, this list contains the type declarations
(<code class="docutils literal notranslate"><span class="pre">l</span></code>, <code class="docutils literal notranslate"><span class="pre">s</span></code> or <code class="docutils literal notranslate"><span class="pre">d</span></code>). Type declarations are specified by appending to the key
name (i.e. <code class="docutils literal notranslate"><span class="pre">level:l</span></code> will search for values of <code class="docutils literal notranslate"><span class="pre">level</span></code> that are longs). Set
to <code class="docutils literal notranslate"><span class="pre">None</span></code> when opening a previously saved grib index file.</p></li>
</ul>
</dd>
</dl>
<dl class="py method">
<dt id="pygrib.index.close">
<code class="sig-name descname">close</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.index.close" title="Permalink to this definition">¶</a></dt>
<dd><p>deallocate C structures associated with class instance</p>
</dd></dl>
<dl class="py method">
<dt id="pygrib.index.select">
<code class="sig-name descname">select</code><span class="sig-paren">(</span><em class="sig-param"><span class="o">**</span><span class="n">kwargs</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.index.select" title="Permalink to this definition">¶</a></dt>
<dd><p>return a list of <a class="reference internal" href="#pygrib.gribmessage" title="pygrib.gribmessage"><code class="xref py py-class docutils literal notranslate"><span class="pre">gribmessage</span></code></a> instances from grib index object
corresponding to specific values of indexed keys (given by kwargs).
Unlike <a class="reference internal" href="#pygrib.open.select" title="pygrib.open.select"><code class="xref py py-meth docutils literal notranslate"><span class="pre">open.select()</span></code></a>, containers or callables cannot be used to
select multiple key values.
However, using <a class="reference internal" href="#pygrib.index.select" title="pygrib.index.select"><code class="xref py py-meth docutils literal notranslate"><span class="pre">index.select()</span></code></a> is much faster than <a class="reference internal" href="#pygrib.open.select" title="pygrib.open.select"><code class="xref py py-meth docutils literal notranslate"><span class="pre">open.select()</span></code></a>.</p>
<p>Example usage:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">pygrib</span>
<span class="gp">>>> </span><span class="n">grbindx</span><span class="o">=</span><span class="n">pygrib</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="s1">'sampledata/gfs.grb'</span><span class="p">,</span><span class="s1">'shortName'</span><span class="p">,</span><span class="s1">'typeOfLevel'</span><span class="p">,</span><span class="s1">'level'</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">selected_grbs</span><span class="o">=</span><span class="n">grbindx</span><span class="o">.</span><span class="n">select</span><span class="p">(</span><span class="n">shortName</span><span class="o">=</span><span class="s1">'gh'</span><span class="p">,</span><span class="n">typeOfLevel</span><span class="o">=</span><span class="s1">'isobaricInhPa'</span><span class="p">,</span><span class="n">level</span><span class="o">=</span><span class="mi">500</span><span class="p">)</span>
<span class="gp">>>> </span><span class="k">for</span> <span class="n">grb</span> <span class="ow">in</span> <span class="n">selected_grbs</span><span class="p">:</span>
<span class="gp">>>> </span> <span class="n">grb</span>
<span class="go">1:Geopotential height:gpm (instant):regular_ll:isobaricInhPa:level 500 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
<span class="gp">>>> </span><span class="c1"># __call__ method does same thing as select</span>
<span class="gp">>>> </span><span class="n">selected_grbs</span><span class="o">=</span><span class="n">grbindx</span><span class="p">(</span><span class="n">shortName</span><span class="o">=</span><span class="s1">'u'</span><span class="p">,</span><span class="n">typeOfLevel</span><span class="o">=</span><span class="s1">'isobaricInhPa'</span><span class="p">,</span><span class="n">level</span><span class="o">=</span><span class="mi">250</span><span class="p">)</span>
<span class="gp">>>> </span><span class="k">for</span> <span class="n">grb</span> <span class="ow">in</span> <span class="n">selected_grbs</span><span class="p">:</span>
<span class="gp">>>> </span> <span class="n">grb</span>
<span class="go">1:u-component of wind:m s**-1 (instant):regular_ll:isobaricInhPa:level 250 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
<span class="gp">>>> </span><span class="n">grbindx</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>
</pre></div>
</div>
</dd></dl>
<dl class="py method">
<dt id="pygrib.index.write">
<code class="sig-name descname">write</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">filename</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.index.write" title="Permalink to this definition">¶</a></dt>
<dd><p>save grib index to file</p>
</dd></dl>
</dd></dl>
<dl class="py function">
<dt id="pygrib.julian_to_datetime">
<code class="sig-prename descclassname">pygrib.</code><code class="sig-name descname">julian_to_datetime</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">julday</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.julian_to_datetime" title="Permalink to this definition">¶</a></dt>
<dd><p>convert Julian day number to python datetime instance.</p>
<p>Used to create <code class="docutils literal notranslate"><span class="pre">validDate</span></code> and <code class="docutils literal notranslate"><span class="pre">analDate</span></code> attributes from
<code class="docutils literal notranslate"><span class="pre">julianDay</span></code> and <code class="docutils literal notranslate"><span class="pre">forecastTime</span></code> keys.</p>
</dd></dl>
<dl class="py function">
<dt id="pygrib.multi_support_off">
<code class="sig-prename descclassname">pygrib.</code><code class="sig-name descname">multi_support_off</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.multi_support_off" title="Permalink to this definition">¶</a></dt>
<dd><p>turn off support for multi-field grib messages</p>
</dd></dl>
<dl class="py function">
<dt id="pygrib.multi_support_on">
<code class="sig-prename descclassname">pygrib.</code><code class="sig-name descname">multi_support_on</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.multi_support_on" title="Permalink to this definition">¶</a></dt>
<dd><p>turn on support for multi-field grib messages (default)</p>
</dd></dl>
<dl class="py class">
<dt id="pygrib.open">
<em class="property">class </em><code class="sig-prename descclassname">pygrib.</code><code class="sig-name descname">open</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">filename</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.open" title="Permalink to this definition">¶</a></dt>
<dd><p>Bases: <a class="reference external" href="https://docs.python.org/3/library/functions.html#object" title="(in Python v3.9)"><code class="xref py py-class docutils literal notranslate"><span class="pre">object</span></code></a></p>
<p>returns GRIB file iterator object given GRIB filename. When iterated, returns
instances of the <a class="reference internal" href="#pygrib.gribmessage" title="pygrib.gribmessage"><code class="xref py py-class docutils literal notranslate"><span class="pre">gribmessage</span></code></a> class. Behaves much like a python file
object, with <a class="reference internal" href="#pygrib.open.seek" title="pygrib.open.seek"><code class="xref py py-meth docutils literal notranslate"><span class="pre">seek()</span></code></a>, <a class="reference internal" href="#pygrib.open.tell" title="pygrib.open.tell"><code class="xref py py-meth docutils literal notranslate"><span class="pre">tell()</span></code></a>, <a class="reference internal" href="#pygrib.open.read" title="pygrib.open.read"><code class="xref py py-meth docutils literal notranslate"><span class="pre">read()</span></code></a>
<a class="reference internal" href="#pygrib.open.readline" title="pygrib.open.readline"><code class="xref py py-meth docutils literal notranslate"><span class="pre">readline()</span></code></a> and <a class="reference internal" href="#pygrib.open.close" title="pygrib.open.close"><code class="xref py py-meth docutils literal notranslate"><span class="pre">close()</span></code></a> methods
except that offsets are measured in grib messages instead of bytes.
Additional methods include <a class="reference internal" href="#pygrib.open.rewind" title="pygrib.open.rewind"><code class="xref py py-meth docutils literal notranslate"><span class="pre">rewind()</span></code></a> (like <code class="docutils literal notranslate"><span class="pre">seek(0)</span></code>),
<a class="reference internal" href="#pygrib.open.message" title="pygrib.open.message"><code class="xref py py-meth docutils literal notranslate"><span class="pre">message()</span></code></a>
(like <code class="docutils literal notranslate"><span class="pre">seek(N-1)</span></code>; followed by <code class="docutils literal notranslate"><span class="pre">readline()</span></code>), and <a class="reference internal" href="#pygrib.open.select" title="pygrib.open.select"><code class="xref py py-meth docutils literal notranslate"><span class="pre">select()</span></code></a> (filters
messages based on specified conditions). The <code class="docutils literal notranslate"><span class="pre">__call__</span></code> method forwards
to <a class="reference internal" href="#pygrib.open.select" title="pygrib.open.select"><code class="xref py py-meth docutils literal notranslate"><span class="pre">select()</span></code></a>, and instances can be sliced with <code class="docutils literal notranslate"><span class="pre">__getitem__</span></code> (returning
lists of <a class="reference internal" href="#pygrib.gribmessage" title="pygrib.gribmessage"><code class="xref py py-class docutils literal notranslate"><span class="pre">gribmessage</span></code></a> instances). The position of the iterator is not
altered by slicing with <code class="docutils literal notranslate"><span class="pre">__getitem__</span></code>.</p>
<dl class="field-list simple">
<dt class="field-odd">Variables</dt>
<dd class="field-odd"><ul class="simple">
<li><p><strong>messages</strong> – The total number of grib messages in the file.</p></li>
<li><p><strong>messagenumber</strong> – The grib message number that the iterator currently
points to (the value returned by <a class="reference internal" href="#pygrib.open.tell" title="pygrib.open.tell"><code class="xref py py-meth docutils literal notranslate"><span class="pre">tell()</span></code></a>).</p></li>
<li><p><strong>name</strong> – The GRIB file which the instance represents.</p></li>
</ul>
</dd>
</dl>
<dl class="py method">
<dt id="pygrib.open.close">
<code class="sig-name descname">close</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.open.close" title="Permalink to this definition">¶</a></dt>
<dd><p>close GRIB file, deallocate C structures associated with class instance</p>
</dd></dl>
<dl class="py method">
<dt id="pygrib.open.message">
<code class="sig-name descname">message</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">N</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.open.message" title="Permalink to this definition">¶</a></dt>
<dd><p>retrieve N’th message in iterator.
same as <code class="docutils literal notranslate"><span class="pre">seek(N-1)</span></code> followed by <code class="docutils literal notranslate"><span class="pre">readline()</span></code>.</p>
</dd></dl>
<dl class="py method">
<dt id="pygrib.open.read">
<code class="sig-name descname">read</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">N</span><span class="o">=</span><span class="default_value">None</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.open.read" title="Permalink to this definition">¶</a></dt>
<dd><p>read N messages from current position, returning grib messages instances in a
list. If N=None, all the messages to the end of the file are read.
<code class="docutils literal notranslate"><span class="pre">pygrib.open(f).read()</span></code> is equivalent to <code class="docutils literal notranslate"><span class="pre">list(pygrib.open(f))</span></code>,
both return a list containing <a class="reference internal" href="#pygrib.gribmessage" title="pygrib.gribmessage"><code class="xref py py-class docutils literal notranslate"><span class="pre">gribmessage</span></code></a> instances for all the
grib messages in the file <code class="docutils literal notranslate"><span class="pre">f</span></code>.</p>
</dd></dl>
<dl class="py method">
<dt id="pygrib.open.readline">
<code class="sig-name descname">readline</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.open.readline" title="Permalink to this definition">¶</a></dt>
<dd><p>read one entire grib message from the file.
Returns a <a class="reference internal" href="#pygrib.gribmessage" title="pygrib.gribmessage"><code class="xref py py-class docutils literal notranslate"><span class="pre">gribmessage</span></code></a> instance, or <code class="docutils literal notranslate"><span class="pre">None</span></code> if an <code class="docutils literal notranslate"><span class="pre">EOF</span></code> is encountered.</p>
</dd></dl>
<dl class="py method">
<dt id="pygrib.open.rewind">
<code class="sig-name descname">rewind</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.open.rewind" title="Permalink to this definition">¶</a></dt>
<dd><p>rewind iterator (same as <code class="docutils literal notranslate"><span class="pre">seek(0)</span></code>)</p>
</dd></dl>
<dl class="py method">
<dt id="pygrib.open.seek">
<code class="sig-name descname">seek</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">N</span></em>, <em class="sig-param"><span class="n">from_what</span><span class="o">=</span><span class="default_value">0</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.open.seek" title="Permalink to this definition">¶</a></dt>
<dd><p>advance iterator N grib messages from beginning of file
(if <code class="docutils literal notranslate"><span class="pre">from_what=0</span></code>), from current position (if <code class="docutils literal notranslate"><span class="pre">from_what=1</span></code>)
or from the end of file (if <code class="docutils literal notranslate"><span class="pre">from_what=2</span></code>).</p>
</dd></dl>
<dl class="py method">
<dt id="pygrib.open.select">
<code class="sig-name descname">select</code><span class="sig-paren">(</span><em class="sig-param"><span class="o">**</span><span class="n">kwargs</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.open.select" title="Permalink to this definition">¶</a></dt>
<dd><p>return a list of <a class="reference internal" href="#pygrib.gribmessage" title="pygrib.gribmessage"><code class="xref py py-class docutils literal notranslate"><span class="pre">gribmessage</span></code></a> instances from iterator filtered by <code class="docutils literal notranslate"><span class="pre">kwargs</span></code>.
If keyword is a container object, each grib message
in the iterator is searched for membership in the container.
If keyword is a callable (has a <code class="docutils literal notranslate"><span class="pre">_call__</span></code> method), each grib
message in the iterator is tested using the callable (which should
return a boolean).
If keyword is not a container object or a callable, each
grib message in the iterator is tested for equality.</p>
<p>Example usage:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">pygrib</span>
<span class="gp">>>> </span><span class="n">grbs</span> <span class="o">=</span> <span class="n">pygrib</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="s1">'sampledata/gfs.grb'</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">selected_grbs</span><span class="o">=</span><span class="n">grbs</span><span class="o">.</span><span class="n">select</span><span class="p">(</span><span class="n">shortName</span><span class="o">=</span><span class="s1">'gh'</span><span class="p">,</span><span class="n">typeOfLevel</span><span class="o">=</span><span class="s1">'isobaricInhPa'</span><span class="p">,</span><span class="n">level</span><span class="o">=</span><span class="mi">10</span><span class="p">)</span>
<span class="gp">>>> </span><span class="k">for</span> <span class="n">grb</span> <span class="ow">in</span> <span class="n">selected_grbs</span><span class="p">:</span> <span class="n">grb</span>
<span class="go">26:Geopotential height:gpm (instant):regular_ll:isobaricInhPa:level 10 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
<span class="gp">>>> </span><span class="c1"># the __call__ method does the same thing</span>
<span class="gp">>>> </span><span class="n">selected_grbs</span><span class="o">=</span><span class="n">grbs</span><span class="p">(</span><span class="n">shortName</span><span class="o">=</span><span class="s1">'gh'</span><span class="p">,</span><span class="n">typeOfLevel</span><span class="o">=</span><span class="s1">'isobaricInhPa'</span><span class="p">,</span><span class="n">level</span><span class="o">=</span><span class="mi">10</span><span class="p">)</span>
<span class="gp">>>> </span><span class="k">for</span> <span class="n">grb</span> <span class="ow">in</span> <span class="n">selected_grbs</span><span class="p">:</span> <span class="n">grb</span>
<span class="go">26:Geopotential height:gpm (instant):regular_ll:isobaricInhPa:level 10 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
<span class="gp">>>> </span><span class="c1"># to select multiple specific key values, use containers (e.g. sequences)</span>
<span class="gp">>>> </span><span class="n">selected_grbs</span><span class="o">=</span><span class="n">grbs</span><span class="p">(</span><span class="n">shortName</span><span class="o">=</span><span class="p">[</span><span class="s1">'u'</span><span class="p">,</span><span class="s1">'v'</span><span class="p">],</span><span class="n">typeOfLevel</span><span class="o">=</span><span class="s1">'isobaricInhPa'</span><span class="p">,</span><span class="n">level</span><span class="o">=</span><span class="p">[</span><span class="mi">10</span><span class="p">,</span><span class="mi">50</span><span class="p">])</span>
<span class="gp">>>> </span><span class="k">for</span> <span class="n">grb</span> <span class="ow">in</span> <span class="n">selected_grbs</span><span class="p">:</span> <span class="n">grb</span>
<span class="go">193:u-component of wind:m s**-1 (instant):regular_ll:isobaricInhPa:level 50 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
<span class="go">194:v-component of wind:m s**-1 (instant):regular_ll:isobaricInhPa:level 50 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
<span class="go">199:u-component of wind:m s**-1 (instant):regular_ll:isobaricInhPa:level 10 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
<span class="go">200:v-component of wind:m s**-1 (instant):regular_ll:isobaricInhPa:level 10 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
<span class="gp">>>> </span><span class="c1"># to select key values based on a conditional expression, use a function</span>
<span class="gp">>>> </span><span class="n">selected_grbs</span><span class="o">=</span><span class="n">grbs</span><span class="p">(</span><span class="n">shortName</span><span class="o">=</span><span class="s1">'gh'</span><span class="p">,</span><span class="n">level</span><span class="o">=</span><span class="k">lambda</span> <span class="n">l</span><span class="p">:</span> <span class="n">l</span> <span class="o"><</span> <span class="mi">500</span> <span class="ow">and</span> <span class="n">l</span> <span class="o">>=</span> <span class="mi">300</span><span class="p">)</span>
<span class="gp">>>> </span><span class="k">for</span> <span class="n">grb</span> <span class="ow">in</span> <span class="n">selected_grbs</span><span class="p">:</span> <span class="n">grb</span>
<span class="go">14:Geopotential height:gpm (instant):regular_ll:isobaricInhPa:level 45000 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
<span class="go">15:Geopotential height:gpm (instant):regular_ll:isobaricInhPa:level 40000 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
<span class="go">16:Geopotential height:gpm (instant):regular_ll:isobaricInhPa:level 35000 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
<span class="go">17:Geopotential height:gpm (instant):regular_ll:isobaricInhPa:level 30000 Pa:fcst time 72 hrs:from 200412091200:lo res cntl fcst</span>
</pre></div>
</div>
</dd></dl>
<dl class="py method">
<dt id="pygrib.open.tell">
<code class="sig-name descname">tell</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.open.tell" title="Permalink to this definition">¶</a></dt>
<dd><p>returns position of iterator (grib message number, 0 means iterator
is positioned at beginning of file).</p>
</dd></dl>
</dd></dl>
<dl class="py function">
<dt id="pygrib.reload">
<code class="sig-prename descclassname">pygrib.</code><code class="sig-name descname">reload</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">grb</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.reload" title="Permalink to this definition">¶</a></dt>
<dd><p>Recreate gribmessage object, updating all the keys to be consistent
with each other. For example, if the <code class="docutils literal notranslate"><span class="pre">forecastTime</span></code> key is changed,
recreating the <a class="reference internal" href="#pygrib.gribmessage" title="pygrib.gribmessage"><code class="xref py py-class docutils literal notranslate"><span class="pre">gribmessage</span></code></a> object with this function will cause
the <code class="docutils literal notranslate"><span class="pre">analDate</span></code> and <code class="docutils literal notranslate"><span class="pre">verifDate</span></code> keys to be updated accordingly.</p>
<p>Equivalent to <code class="docutils literal notranslate"><span class="pre">fromstring(grb.tostring())</span></code></p>
</dd></dl>
<dl class="py function">
<dt id="pygrib.set_definitions_path">
<code class="sig-prename descclassname">pygrib.</code><code class="sig-name descname">set_definitions_path</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.set_definitions_path" title="Permalink to this definition">¶</a></dt>
<dd><p>set_definition_path(ECCODES_DEFINITION_PATH)</p>
<p>set path to eccodes definition files (grib tables).</p>
</dd></dl>
<dl class="py function">
<dt id="pygrib.setdates">
<code class="sig-prename descclassname">pygrib.</code><code class="sig-name descname">setdates</code><span class="sig-paren">(</span><em class="sig-param"><span class="n">grb</span></em><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.setdates" title="Permalink to this definition">¶</a></dt>
<dd><p>set <code class="docutils literal notranslate"><span class="pre">fcstimeunits</span></code>, <code class="docutils literal notranslate"><span class="pre">analDate</span></code> and <code class="docutils literal notranslate"><span class="pre">validDate</span></code> attributes using
the <code class="docutils literal notranslate"><span class="pre">julianDay</span></code>, <code class="docutils literal notranslate"><span class="pre">forecastTime</span></code> and <code class="docutils literal notranslate"><span class="pre">indicatorOfUnitOfTimeRange</span></code> keys.
Called automatically when <a class="reference internal" href="#pygrib.gribmessage" title="pygrib.gribmessage"><code class="xref py py-class docutils literal notranslate"><span class="pre">gribmessage</span></code></a> instance created,
but can be called manually to update keys if one of
them is modified after instance creation.</p>
</dd></dl>
<dl class="py function">
<dt id="pygrib.tolerate_badgrib_off">
<code class="sig-prename descclassname">pygrib.</code><code class="sig-name descname">tolerate_badgrib_off</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.tolerate_badgrib_off" title="Permalink to this definition">¶</a></dt>
<dd><p>raise an exception when a missing or malformed key is encountered
(default behavior).</p>
</dd></dl>
<dl class="py function">
<dt id="pygrib.tolerate_badgrib_on">
<code class="sig-prename descclassname">pygrib.</code><code class="sig-name descname">tolerate_badgrib_on</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pygrib.tolerate_badgrib_on" title="Permalink to this definition">¶</a></dt>
<dd><p>don’t raise an exception when a missing or malformed key is encountered.</p>
</dd></dl>
</div>
</div>
<div class="clearer"></div>
</div>
</div>
</div>
<div class="sphinxsidebar" role="navigation" aria-label="main navigation">
<div class="sphinxsidebarwrapper">
<h3><a href="index.html">Table of Contents</a></h3>
<ul>
<li><a class="reference internal" href="#">API</a><ul>
<li><a class="reference internal" href="#example-usage">Example usage</a></li>
<li><a class="reference internal" href="#module-pygrib">Module docstrings</a></li>
</ul>
</li>
</ul>
<h4>Previous topic</h4>
<p class="topless"><a href="installing.html"
title="previous chapter">Installation</a></p>
<div role="note" aria-label="source link">
<h3>This Page</h3>
<ul class="this-page-menu">
<li><a href="_sources/api.rst.txt"
rel="nofollow">Show Source</a></li>
</ul>
</div>
<div id="searchbox" style="display: none" role="search">
<h3 id="searchlabel">Quick search</h3>
<div class="searchformwrapper">
<form class="search" action="search.html" method="get">
<input type="text" name="q" aria-labelledby="searchlabel" />
<input type="submit" value="Go" />
</form>
</div>
</div>
<script>$('#searchbox').show(0);</script>
</div>
</div>
<div class="clearer"></div>
</div>
<div class="related" role="navigation" aria-label="related navigation">
<h3>Navigation</h3>
<ul>
<li class="right" style="margin-right: 10px">
<a href="genindex.html" title="General Index"
>index</a></li>
<li class="right" >
<a href="py-modindex.html" title="Python Module Index"
>modules</a> |</li>
<li class="right" >
<a href="installing.html" title="Installation"
>previous</a> |</li>
<li class="nav-item nav-item-0"><a href="index.html">pygrib documentation</a> »</li>
<li class="nav-item nav-item-this"><a href="">API</a></li>
</ul>
</div>
<div class="footer" role="contentinfo">
© Copyright 2018, Jeff Whitaker.
Created using <a href="https://www.sphinx-doc.org/">Sphinx</a> 3.3.1.
</div>
</body>
</html>
|
