File: test_contrib_loader.py

package info (click to toggle)
python-scrapy 0.24.2-1
  • links: PTS, VCS
  • area: main
  • in suites: jessie, jessie-kfreebsd
  • size: 3,240 kB
  • ctags: 4,259
  • sloc: python: 21,170; xml: 199; makefile: 67; sh: 44
file content (583 lines) | stat: -rw-r--r-- 22,570 bytes parent folder | download
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
582
583
import unittest
from functools import partial

from scrapy.contrib.loader import ItemLoader
from scrapy.contrib.loader.processor import Join, Identity, TakeFirst, \
    Compose, MapCompose
from scrapy.item import Item, Field
from scrapy.selector import Selector
from scrapy.http import HtmlResponse


# test items
class NameItem(Item):
    name = Field()


class TestItem(NameItem):
    url = Field()
    summary = Field()


# test item loaders
class NameItemLoader(ItemLoader):
    default_item_class = TestItem


class TestItemLoader(NameItemLoader):
    name_in = MapCompose(lambda v: v.title())


class DefaultedItemLoader(NameItemLoader):
    default_input_processor = MapCompose(lambda v: v[:-1])


# test processors
def processor_with_args(value, other=None, loader_context=None):
    if 'key' in loader_context:
        return loader_context['key']
    return value


class BasicItemLoaderTest(unittest.TestCase):

    def test_load_item_using_default_loader(self):
        i = TestItem()
        i['summary'] = u'lala'
        il = ItemLoader(item=i)
        il.add_value('name', u'marta')
        item = il.load_item()
        assert item is i
        self.assertEqual(item['summary'], u'lala')
        self.assertEqual(item['name'], [u'marta'])

    def test_load_item_using_custom_loader(self):
        il = TestItemLoader()
        il.add_value('name', u'marta')
        item = il.load_item()
        self.assertEqual(item['name'], [u'Marta'])

    def test_load_item_ignore_none_field_values(self):
        def validate_sku(value):
            # Let's assume a SKU is only digits.
            if value.isdigit():
                return value

        class MyLoader(ItemLoader):
            name_out = Compose(lambda vs: vs[0])  # take first which allows empty values
            price_out = Compose(TakeFirst(), float)
            sku_out = Compose(TakeFirst(), validate_sku)

        valid_fragment = u'SKU: 1234'
        invalid_fragment = u'SKU: not available'
        sku_re = 'SKU: (.+)'

        il = MyLoader(item={})
        # Should not return "sku: None".
        il.add_value('sku', [invalid_fragment], re=sku_re)
        # Should not ignore empty values.
        il.add_value('name', u'')
        il.add_value('price', [u'0'])
        self.assertEqual(il.load_item(), {
            'name': u'',
            'price': 0.0,
        })

        il.replace_value('sku', [valid_fragment], re=sku_re)
        self.assertEqual(il.load_item()['sku'], u'1234')

    def test_add_value(self):
        il = TestItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_collected_values('name'), [u'Marta'])
        self.assertEqual(il.get_output_value('name'), [u'Marta'])
        il.add_value('name', u'pepe')
        self.assertEqual(il.get_collected_values('name'), [u'Marta', u'Pepe'])
        self.assertEqual(il.get_output_value('name'), [u'Marta', u'Pepe'])

        # test add object value
        il.add_value('summary', {'key': 1})
        self.assertEqual(il.get_collected_values('summary'), [{'key': 1}])

        il.add_value(None, u'Jim', lambda x: {'name': x})
        self.assertEqual(il.get_collected_values('name'), [u'Marta', u'Pepe', u'Jim'])

    def test_add_zero(self):
        il = NameItemLoader()
        il.add_value('name', 0)
        self.assertEqual(il.get_collected_values('name'), [0])

    def test_replace_value(self):
        il = TestItemLoader()
        il.replace_value('name', u'marta')
        self.assertEqual(il.get_collected_values('name'), [u'Marta'])
        self.assertEqual(il.get_output_value('name'), [u'Marta'])
        il.replace_value('name', u'pepe')
        self.assertEqual(il.get_collected_values('name'), [u'Pepe'])
        self.assertEqual(il.get_output_value('name'), [u'Pepe'])

        il.replace_value(None, u'Jim', lambda x: {'name': x})
        self.assertEqual(il.get_collected_values('name'), [u'Jim'])

    def test_get_value(self):
        il = NameItemLoader()
        self.assertEqual(u'FOO', il.get_value([u'foo', u'bar'], TakeFirst(), unicode.upper))
        self.assertEqual([u'foo', u'bar'], il.get_value([u'name:foo', u'name:bar'], re=u'name:(.*)$'))
        self.assertEqual(u'foo', il.get_value([u'name:foo', u'name:bar'], TakeFirst(), re=u'name:(.*)$'))

        il.add_value('name', [u'name:foo', u'name:bar'], TakeFirst(), re=u'name:(.*)$')
        self.assertEqual([u'foo'], il.get_collected_values('name'))
        il.replace_value('name', u'name:bar', re=u'name:(.*)$')
        self.assertEqual([u'bar'], il.get_collected_values('name'))

    def test_iter_on_input_processor_input(self):
        class NameFirstItemLoader(NameItemLoader):
            name_in = TakeFirst()

        il = NameFirstItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_collected_values('name'), [u'marta'])
        il = NameFirstItemLoader()
        il.add_value('name', [u'marta', u'jose'])
        self.assertEqual(il.get_collected_values('name'), [u'marta'])

        il = NameFirstItemLoader()
        il.replace_value('name', u'marta')
        self.assertEqual(il.get_collected_values('name'), [u'marta'])
        il = NameFirstItemLoader()
        il.replace_value('name', [u'marta', u'jose'])
        self.assertEqual(il.get_collected_values('name'), [u'marta'])

        il = NameFirstItemLoader()
        il.add_value('name', u'marta')
        il.add_value('name', [u'jose', u'pedro'])
        self.assertEqual(il.get_collected_values('name'), [u'marta', u'jose'])

    def test_map_compose_filter(self):
        def filter_world(x):
            return None if x == 'world' else x

        proc = MapCompose(filter_world, str.upper)
        self.assertEqual(proc(['hello', 'world', 'this', 'is', 'scrapy']),
                         ['HELLO', 'THIS', 'IS', 'SCRAPY'])

    def test_map_compose_filter_multil(self):
        class TestItemLoader(NameItemLoader):
            name_in = MapCompose(lambda v: v.title(), lambda v: v[:-1])

        il = TestItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'Mart'])
        item = il.load_item()
        self.assertEqual(item['name'], [u'Mart'])

    def test_default_input_processor(self):
        il = DefaultedItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'mart'])

    def test_inherited_default_input_processor(self):
        class InheritDefaultedItemLoader(DefaultedItemLoader):
            pass

        il = InheritDefaultedItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'mart'])

    def test_input_processor_inheritance(self):
        class ChildItemLoader(TestItemLoader):
            url_in = MapCompose(lambda v: v.lower())

        il = ChildItemLoader()
        il.add_value('url', u'HTTP://scrapy.ORG')
        self.assertEqual(il.get_output_value('url'), [u'http://scrapy.org'])
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'Marta'])

        class ChildChildItemLoader(ChildItemLoader):
            url_in = MapCompose(lambda v: v.upper())
            summary_in = MapCompose(lambda v: v)

        il = ChildChildItemLoader()
        il.add_value('url', u'http://scrapy.org')
        self.assertEqual(il.get_output_value('url'), [u'HTTP://SCRAPY.ORG'])
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'Marta'])

    def test_empty_map_compose(self):
        class IdentityDefaultedItemLoader(DefaultedItemLoader):
            name_in = MapCompose()

        il = IdentityDefaultedItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'marta'])

    def test_identity_input_processor(self):
        class IdentityDefaultedItemLoader(DefaultedItemLoader):
            name_in = Identity()

        il = IdentityDefaultedItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'marta'])

    def test_extend_custom_input_processors(self):
        class ChildItemLoader(TestItemLoader):
            name_in = MapCompose(TestItemLoader.name_in, unicode.swapcase)

        il = ChildItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'mARTA'])

    def test_extend_default_input_processors(self):
        class ChildDefaultedItemLoader(DefaultedItemLoader):
            name_in = MapCompose(DefaultedItemLoader.default_input_processor, unicode.swapcase)

        il = ChildDefaultedItemLoader()
        il.add_value('name', u'marta')
        self.assertEqual(il.get_output_value('name'), [u'MART'])

    def test_output_processor_using_function(self):
        il = TestItemLoader()
        il.add_value('name', [u'mar', u'ta'])
        self.assertEqual(il.get_output_value('name'), [u'Mar', u'Ta'])

        class TakeFirstItemLoader(TestItemLoader):
            name_out = u" ".join

        il = TakeFirstItemLoader()
        il.add_value('name', [u'mar', u'ta'])
        self.assertEqual(il.get_output_value('name'), u'Mar Ta')

    def test_output_processor_error(self):
        class TestItemLoader(ItemLoader):
            default_item_class = TestItem
            name_out = MapCompose(float)

        il = TestItemLoader()
        il.add_value('name', [u'$10'])
        try:
            float('$10')
        except Exception as e:
            expected_exc_str = str(e)

        exc = None
        try:
            il.load_item()
        except Exception as e:
            exc = e
        assert isinstance(exc, ValueError)
        s = str(exc)
        assert 'name' in s, s
        assert '$10' in s, s
        assert 'ValueError' in s, s
        assert expected_exc_str in s, s

    def test_output_processor_using_classes(self):
        il = TestItemLoader()
        il.add_value('name', [u'mar', u'ta'])
        self.assertEqual(il.get_output_value('name'), [u'Mar', u'Ta'])

        class TakeFirstItemLoader(TestItemLoader):
            name_out = Join()

        il = TakeFirstItemLoader()
        il.add_value('name', [u'mar', u'ta'])
        self.assertEqual(il.get_output_value('name'), u'Mar Ta')

        class TakeFirstItemLoader(TestItemLoader):
            name_out = Join("<br>")

        il = TakeFirstItemLoader()
        il.add_value('name', [u'mar', u'ta'])
        self.assertEqual(il.get_output_value('name'), u'Mar<br>Ta')

    def test_default_output_processor(self):
        il = TestItemLoader()
        il.add_value('name', [u'mar', u'ta'])
        self.assertEqual(il.get_output_value('name'), [u'Mar', u'Ta'])

        class LalaItemLoader(TestItemLoader):
            default_output_processor = Identity()

        il = LalaItemLoader()
        il.add_value('name', [u'mar', u'ta'])
        self.assertEqual(il.get_output_value('name'), [u'Mar', u'Ta'])

    def test_loader_context_on_declaration(self):
        class ChildItemLoader(TestItemLoader):
            url_in = MapCompose(processor_with_args, key=u'val')

        il = ChildItemLoader()
        il.add_value('url', u'text')
        self.assertEqual(il.get_output_value('url'), ['val'])
        il.replace_value('url', u'text2')
        self.assertEqual(il.get_output_value('url'), ['val'])

    def test_loader_context_on_instantiation(self):
        class ChildItemLoader(TestItemLoader):
            url_in = MapCompose(processor_with_args)

        il = ChildItemLoader(key=u'val')
        il.add_value('url', u'text')
        self.assertEqual(il.get_output_value('url'), ['val'])
        il.replace_value('url', u'text2')
        self.assertEqual(il.get_output_value('url'), ['val'])

    def test_loader_context_on_assign(self):
        class ChildItemLoader(TestItemLoader):
            url_in = MapCompose(processor_with_args)

        il = ChildItemLoader()
        il.context['key'] = u'val'
        il.add_value('url', u'text')
        self.assertEqual(il.get_output_value('url'), ['val'])
        il.replace_value('url', u'text2')
        self.assertEqual(il.get_output_value('url'), ['val'])

    def test_item_passed_to_input_processor_functions(self):
        def processor(value, loader_context):
            return loader_context['item']['name']

        class ChildItemLoader(TestItemLoader):
            url_in = MapCompose(processor)

        it = TestItem(name='marta')
        il = ChildItemLoader(item=it)
        il.add_value('url', u'text')
        self.assertEqual(il.get_output_value('url'), ['marta'])
        il.replace_value('url', u'text2')
        self.assertEqual(il.get_output_value('url'), ['marta'])

    def test_add_value_on_unknown_field(self):
        il = TestItemLoader()
        self.assertRaises(KeyError, il.add_value, 'wrong_field', [u'lala', u'lolo'])

    def test_compose_processor(self):
        class TestItemLoader(NameItemLoader):
            name_out = Compose(lambda v: v[0], lambda v: v.title(), lambda v: v[:-1])

        il = TestItemLoader()
        il.add_value('name', [u'marta', u'other'])
        self.assertEqual(il.get_output_value('name'), u'Mart')
        item = il.load_item()
        self.assertEqual(item['name'], u'Mart')

    def test_partial_processor(self):
        def join(values, sep=None, loader_context=None, ignored=None):
            if sep is not None:
                return sep.join(values)
            elif loader_context and 'sep' in loader_context:
                return loader_context['sep'].join(values)
            else:
                return ''.join(values)

        class TestItemLoader(NameItemLoader):
            name_out = Compose(partial(join, sep='+'))
            url_out = Compose(partial(join, loader_context={'sep': '.'}))
            summary_out = Compose(partial(join, ignored='foo'))

        il = TestItemLoader()
        il.add_value('name', [u'rabbit', u'hole'])
        il.add_value('url', [u'rabbit', u'hole'])
        il.add_value('summary', [u'rabbit', u'hole'])
        item = il.load_item()
        self.assertEqual(item['name'], u'rabbit+hole')
        self.assertEqual(item['url'], u'rabbit.hole')
        self.assertEqual(item['summary'], u'rabbithole')


class ProcessorsTest(unittest.TestCase):

    def test_take_first(self):
        proc = TakeFirst()
        self.assertEqual(proc([None, '', 'hello', 'world']), 'hello')
        self.assertEqual(proc([None, '', 0, 'hello', 'world']), 0)

    def test_identity(self):
        proc = Identity()
        self.assertEqual(proc([None, '', 'hello', 'world']),
                         [None, '', 'hello', 'world'])

    def test_join(self):
        proc = Join()
        self.assertRaises(TypeError, proc, [None, '', 'hello', 'world'])
        self.assertEqual(proc(['', 'hello', 'world']), u' hello world')
        self.assertEqual(proc(['hello', 'world']), u'hello world')
        self.assert_(isinstance(proc(['hello', 'world']), unicode))

    def test_compose(self):
        proc = Compose(lambda v: v[0], str.upper)
        self.assertEqual(proc(['hello', 'world']), 'HELLO')
        proc = Compose(str.upper)
        self.assertEqual(proc(None), None)
        proc = Compose(str.upper, stop_on_none=False)
        self.assertRaises(TypeError, proc, None)

    def test_mapcompose(self):
        filter_world = lambda x: None if x == 'world' else x
        proc = MapCompose(filter_world, unicode.upper)
        self.assertEqual(proc([u'hello', u'world', u'this', u'is', u'scrapy']),
                         [u'HELLO', u'THIS', u'IS', u'SCRAPY'])


class SelectortemLoaderTest(unittest.TestCase):
    response = HtmlResponse(url="", body="""
    <html>
    <body>
    <div id="id">marta</div>
    <p>paragraph</p>
    <a href="http://www.scrapy.org">homepage</a>
    <img src="/images/logo.png" width="244" height="65" alt="Scrapy">
    </body>
    </html>
    """)

    def test_constructor(self):
        l = TestItemLoader()
        self.assertEqual(l.selector, None)

    def test_constructor_errors(self):
        l = TestItemLoader()
        self.assertRaises(RuntimeError, l.add_xpath, 'url', '//a/@href')
        self.assertRaises(RuntimeError, l.replace_xpath, 'url', '//a/@href')
        self.assertRaises(RuntimeError, l.get_xpath, '//a/@href')
        self.assertRaises(RuntimeError, l.add_css, 'name', '#name::text')
        self.assertRaises(RuntimeError, l.replace_css, 'name', '#name::text')
        self.assertRaises(RuntimeError, l.get_css, '#name::text')

    def test_constructor_with_selector(self):
        sel = Selector(text=u"<html><body><div>marta</div></body></html>")
        l = TestItemLoader(selector=sel)
        self.assert_(l.selector is sel)

        l.add_xpath('name', '//div/text()')
        self.assertEqual(l.get_output_value('name'), [u'Marta'])

    def test_constructor_with_selector_css(self):
        sel = Selector(text=u"<html><body><div>marta</div></body></html>")
        l = TestItemLoader(selector=sel)
        self.assert_(l.selector is sel)

        l.add_css('name', 'div::text')
        self.assertEqual(l.get_output_value('name'), [u'Marta'])

    def test_constructor_with_response(self):
        l = TestItemLoader(response=self.response)
        self.assert_(l.selector)

        l.add_xpath('name', '//div/text()')
        self.assertEqual(l.get_output_value('name'), [u'Marta'])

    def test_constructor_with_response_css(self):
        l = TestItemLoader(response=self.response)
        self.assert_(l.selector)

        l.add_css('name', 'div::text')
        self.assertEqual(l.get_output_value('name'), [u'Marta'])

        l.add_css('url', 'a::attr(href)')
        self.assertEqual(l.get_output_value('url'), [u'http://www.scrapy.org'])

        # combining/accumulating CSS selectors and XPath expressions
        l.add_xpath('name', '//div/text()')
        self.assertEqual(l.get_output_value('name'), [u'Marta', u'Marta'])

        l.add_xpath('url', '//img/@src')
        self.assertEqual(l.get_output_value('url'), [u'http://www.scrapy.org', u'/images/logo.png'])

    def test_add_xpath_re(self):
        l = TestItemLoader(response=self.response)
        l.add_xpath('name', '//div/text()', re='ma')
        self.assertEqual(l.get_output_value('name'), [u'Ma'])

    def test_replace_xpath(self):
        l = TestItemLoader(response=self.response)
        self.assert_(l.selector)
        l.add_xpath('name', '//div/text()')
        self.assertEqual(l.get_output_value('name'), [u'Marta'])
        l.replace_xpath('name', '//p/text()')
        self.assertEqual(l.get_output_value('name'), [u'Paragraph'])

        l.replace_xpath('name', ['//p/text()', '//div/text()'])
        self.assertEqual(l.get_output_value('name'), [u'Paragraph', 'Marta'])

    def test_get_xpath(self):
        l = TestItemLoader(response=self.response)
        self.assertEqual(l.get_xpath('//p/text()'), [u'paragraph'])
        self.assertEqual(l.get_xpath('//p/text()', TakeFirst()), u'paragraph')
        self.assertEqual(l.get_xpath('//p/text()', TakeFirst(), re='pa'), u'pa')

        self.assertEqual(l.get_xpath(['//p/text()', '//div/text()']), [u'paragraph', 'marta'])

    def test_replace_xpath_multi_fields(self):
        l = TestItemLoader(response=self.response)
        l.add_xpath(None, '//div/text()', TakeFirst(), lambda x: {'name': x})
        self.assertEqual(l.get_output_value('name'), [u'Marta'])
        l.replace_xpath(None, '//p/text()', TakeFirst(), lambda x: {'name': x})
        self.assertEqual(l.get_output_value('name'), [u'Paragraph'])

    def test_replace_xpath_re(self):
        l = TestItemLoader(response=self.response)
        self.assert_(l.selector)
        l.add_xpath('name', '//div/text()')
        self.assertEqual(l.get_output_value('name'), [u'Marta'])
        l.replace_xpath('name', '//div/text()', re='ma')
        self.assertEqual(l.get_output_value('name'), [u'Ma'])

    def test_add_css_re(self):
        l = TestItemLoader(response=self.response)
        l.add_css('name', 'div::text', re='ma')
        self.assertEqual(l.get_output_value('name'), [u'Ma'])

        l.add_css('url', 'a::attr(href)', re='http://(.+)')
        self.assertEqual(l.get_output_value('url'), [u'www.scrapy.org'])

    def test_replace_css(self):
        l = TestItemLoader(response=self.response)
        self.assert_(l.selector)
        l.add_css('name', 'div::text')
        self.assertEqual(l.get_output_value('name'), [u'Marta'])
        l.replace_css('name', 'p::text')
        self.assertEqual(l.get_output_value('name'), [u'Paragraph'])

        l.replace_css('name', ['p::text', 'div::text'])
        self.assertEqual(l.get_output_value('name'), [u'Paragraph', 'Marta'])

        l.add_css('url', 'a::attr(href)', re='http://(.+)')
        self.assertEqual(l.get_output_value('url'), [u'www.scrapy.org'])
        l.replace_css('url', 'img::attr(src)')
        self.assertEqual(l.get_output_value('url'), [u'/images/logo.png'])

    def test_get_css(self):
        l = TestItemLoader(response=self.response)
        self.assertEqual(l.get_css('p::text'), [u'paragraph'])
        self.assertEqual(l.get_css('p::text', TakeFirst()), u'paragraph')
        self.assertEqual(l.get_css('p::text', TakeFirst(), re='pa'), u'pa')

        self.assertEqual(l.get_css(['p::text', 'div::text']), [u'paragraph', 'marta'])
        self.assertEqual(l.get_css(['a::attr(href)', 'img::attr(src)']),
            [u'http://www.scrapy.org', u'/images/logo.png'])

    def test_replace_css_multi_fields(self):
        l = TestItemLoader(response=self.response)
        l.add_css(None, 'div::text', TakeFirst(), lambda x: {'name': x})
        self.assertEqual(l.get_output_value('name'), [u'Marta'])
        l.replace_css(None, 'p::text', TakeFirst(), lambda x: {'name': x})
        self.assertEqual(l.get_output_value('name'), [u'Paragraph'])

        l.add_css(None, 'a::attr(href)', TakeFirst(), lambda x: {'url': x})
        self.assertEqual(l.get_output_value('url'), [u'http://www.scrapy.org'])
        l.replace_css(None, 'img::attr(src)', TakeFirst(), lambda x: {'url': x})
        self.assertEqual(l.get_output_value('url'), [u'/images/logo.png'])

    def test_replace_css_re(self):
        l = TestItemLoader(response=self.response)
        self.assert_(l.selector)
        l.add_css('url', 'a::attr(href)')
        self.assertEqual(l.get_output_value('url'), [u'http://www.scrapy.org'])
        l.replace_css('url', 'a::attr(href)', re='http://www\.(.+)')
        self.assertEqual(l.get_output_value('url'), [u'scrapy.org'])


if __name__ == "__main__":
    unittest.main()