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to_datetime should support ISO week year

See original GitHub issue

to_datetime does not currently seem to support ISO week year like strptime does:

In [38]: datetime.date(2016, 1, 1).strftime('%G-%V')
Out[38]: '2015-53'

In [39]: datetime.datetime.strptime(datetime.date(2016, 1, 1).strftime('%G-%V')+'-1', '%G-%V-%u')
Out[39]: datetime.datetime(2015, 12, 28, 0, 0)

In [41]: pd.to_datetime(datetime.date(2016, 1, 1).strftime('%G-%V')+'-1', format='%G-%V-%u')
        ---------------------------------------------------------------------------
        TypeError                                 Traceback (most recent call last)
        /Users/Robin/.pyenv/versions/3.6.1/lib/python3.6/site-packages/pandas/core/tools/datetimes.py in _convert_listlike(arg, box, format, name, tz)
            443             try:
        --> 444                 values, tz = tslib.datetime_to_datetime64(arg)
            445                 return DatetimeIndex._simple_new(values, name=name, tz=tz)

        pandas/_libs/tslib.pyx in pandas._libs.tslib.datetime_to_datetime64 (pandas/_libs/tslib.c:33275)()

        TypeError: Unrecognized value type: <class 'str'>

        During handling of the above exception, another exception occurred:

        ValueError                                Traceback (most recent call last)
        <ipython-input-41-7ce30c959690> in <module>()
        ----> 1 pd.to_datetime(datetime.date(2016, 1, 1).strftime('%G-%V')+'-1', format='%G-%V-%u')

        /Users/Robin/.pyenv/versions/3.6.1/lib/python3.6/site-packages/pandas/core/tools/datetimes.py in to_datetime(arg, errors, dayfirst, yearfirst, utc, box, format, exact, unit, infer_datetime_format, origin)
            516         result = _convert_listlike(arg, box, format)
            517     else:
        --> 518         result = _convert_listlike(np.array([arg]), box, format)[0]
            519 
            520     return result

        /Users/Robin/.pyenv/versions/3.6.1/lib/python3.6/site-packages/pandas/core/tools/datetimes.py in _convert_listlike(arg, box, format, name, tz)
            445                 return DatetimeIndex._simple_new(values, name=name, tz=tz)
            446             except (ValueError, TypeError):
        --> 447                 raise e
            448 
            449     if arg is None:

        /Users/Robin/.pyenv/versions/3.6.1/lib/python3.6/site-packages/pandas/core/tools/datetimes.py in _convert_listlike(arg, box, format, name, tz)
            412                     try:
            413                         result = tslib.array_strptime(arg, format, exact=exact,
        --> 414                                                       errors=errors)
            415                     except tslib.OutOfBoundsDatetime:
            416                         if errors == 'raise':

        pandas/_libs/tslib.pyx in pandas._libs.tslib.array_strptime (pandas/_libs/tslib.c:63124)()

        pandas/_libs/tslib.pyx in pandas._libs.tslib.array_strptime (pandas/_libs/tslib.c:63003)()

        ValueError: 'G' is a bad directive in format '%G-%V-%u'

INSTALLED VERSIONS ------------------ commit: None

pandas: 0.20.1 pytest: 3.1.0 pip: 9.0.1 setuptools: 28.8.0 Cython: 0.25.2 numpy: 1.12.1 scipy: 0.19.0 xarray: None IPython: 6.0.0 sphinx: None patsy: 0.4.1 dateutil: 2.6.0 pytz: 2017.2 blosc: None bottleneck: None tables: 3.4.2 numexpr: 2.6.2 feather: None matplotlib: 2.0.2 openpyxl: None xlrd: None xlwt: None xlsxwriter: None lxml: None bs4: None html5lib: 0.999999999 sqlalchemy: 1.1.10 pymysql: None psycopg2: 2.7.1 (dt dec pq3 ext lo64) jinja2: 2.9.6 s3fs: None pandas_gbq: None pandas_datareader: None

Issue Analytics

State:
Created 6 years ago
Comments:15 (6 by maintainers)

Top GitHub Comments

1reaction

TomAugspurgercommented, Jun 8, 2017

@rosygupta this is a new feature request, so there aren’t existing tests for it. Similar tests to what you would need to add are in https://github.com/pandas-dev/pandas/blob/73930c58e8eac4031608bb8c4bf624d77e1d1dcb/pandas/tests/indexes/datetimes/test_tools.py

1reaction

buyologycommented, Jun 7, 2017

@rosygupta it involves some cython, but should be pretty straightforward as long as you get the environment up and running properly. otherwise, if you want something more lightweight, go and look for novice-labeled issues 🚀

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