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
|
import numpy as np
import pandas as pd
from pytz import timezone as get_timezone
from .base import NumpyColumn
from ...util.compat import get_localzone_name_compat
class NumpyDateTimeColumnBase(NumpyColumn):
datetime_dtype = None
null_value = np.datetime64(0, 'Y')
def __init__(self, timezone=None, offset_naive=True, local_timezone=None,
**kwargs):
self.timezone = timezone
self.offset_naive = offset_naive
self.local_timezone = local_timezone
super(NumpyDateTimeColumnBase, self).__init__(**kwargs)
def apply_timezones_after_read(self, dt):
timezone = self.timezone if self.timezone else self.local_timezone
ts = pd.to_datetime(dt, utc=True).tz_convert(timezone)
if self.offset_naive:
ts = ts.tz_localize(None)
return ts.to_numpy(self.datetime_dtype)
def apply_timezones_before_write(self, items):
if isinstance(items, pd.DatetimeIndex):
ts = items
else:
timezone = self.timezone if self.timezone else self.local_timezone
ts = pd.to_datetime(items).tz_localize(timezone)
ts = ts.tz_convert('UTC')
return ts.tz_localize(None).to_numpy(self.datetime_dtype)
def is_items_integer(self, items):
return (
isinstance(items, np.ndarray) and
np.issubdtype(items.dtype, np.integer)
)
class NumpyDateTimeColumn(NumpyDateTimeColumnBase):
dtype = np.dtype(np.uint32)
datetime_dtype = 'datetime64[s]'
def write_items(self, items, buf):
# write int 'as is'.
if self.is_items_integer(items):
super(NumpyDateTimeColumn, self).write_items(items, buf)
return
items = self.apply_timezones_before_write(items)
super(NumpyDateTimeColumn, self).write_items(items, buf)
def read_items(self, n_items, buf):
items = super(NumpyDateTimeColumn, self).read_items(n_items, buf)
return self.apply_timezones_after_read(items.astype('datetime64[s]'))
class NumpyDateTime64Column(NumpyDateTimeColumnBase):
dtype = np.dtype(np.uint64)
datetime_dtype = 'datetime64[ns]'
max_scale = 9
def __init__(self, scale=0, **kwargs):
self.scale = scale
super(NumpyDateTime64Column, self).__init__(**kwargs)
def read_items(self, n_items, buf):
scale = 10 ** self.scale
frac_scale = 10 ** (self.max_scale - self.scale)
items = super(NumpyDateTime64Column, self).read_items(n_items, buf)
seconds = (items // scale).astype('datetime64[s]')
microseconds = ((items % scale) * frac_scale).astype('timedelta64[ns]')
dt = seconds + microseconds
return self.apply_timezones_after_read(dt)
def write_items(self, items, buf):
# write int 'as is'.
if self.is_items_integer(items):
super(NumpyDateTime64Column, self).write_items(items, buf)
return
scale = 10 ** self.scale
frac_scale = 10 ** (self.max_scale - self.scale)
items = self.apply_timezones_before_write(items)
seconds = items.astype('datetime64[s]')
microseconds = (items - seconds).astype(dtype='timedelta64[ns]') \
.astype(np.uint32) // frac_scale
items = seconds.astype(self.dtype) * scale + microseconds
super(NumpyDateTime64Column, self).write_items(items, buf)
def create_numpy_datetime_column(spec, column_options):
if spec.startswith('DateTime64'):
cls = NumpyDateTime64Column
spec = spec[11:-1]
params = spec.split(',', 1)
column_options['scale'] = int(params[0])
if len(params) > 1:
spec = params[1].strip() + ')'
else:
cls = NumpyDateTimeColumn
spec = spec[9:]
context = column_options['context']
tz_name = timezone = None
offset_naive = True
# As Numpy do not use local timezone for converting timestamp to
# datetime we need always detect local timezone for manual converting.
local_timezone = get_localzone_name_compat()
# Use column's timezone if it's specified.
if spec and spec[-1] == ')':
tz_name = spec[1:-2]
offset_naive = False
else:
if not context.settings.get('use_client_time_zone', False):
if local_timezone != context.server_info.timezone:
tz_name = context.server_info.timezone
if tz_name:
timezone = get_timezone(tz_name)
return cls(timezone=timezone, offset_naive=offset_naive,
local_timezone=local_timezone, **column_options)
|