CODEWITHSUNDEEP
pythonpandastime
Breton
Breton

Reputation: 15

pandas.to_datetime ValueError: cannot assemble the datetimes

I'm trying to create a pandas datetime series using 3 pandas columns. When I call the to_datetime() method, it throws an error, even though I'm feeding it series inputs of int64 dtypes in proper year, month, day format.

pd.to_datetime(df[['year', 'month', 'day']])

The last line of the error stack is the weirdest, because it seems to show my values are of %Y%m%d format, yet it won't accept them.

---------------------------------------------------------------------------

TypeError                                 Traceback (most recent call last)

/opt/python/python35/lib/python3.5/site-packages/pandas/core/tools/datetimes.py in _convert_listlike(arg, box, format, name, tz)

    302             try:

--> 303                 values, tz = tslib.datetime_to_datetime64(arg)

    304                 return DatetimeIndex._simple_new(values, name=name, tz=tz)



pandas/_libs/tslib.pyx in pandas._libs.tslib.datetime_to_datetime64()



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



During handling of the above exception, another exception occurred:



ValueError                                Traceback (most recent call last)

/opt/python/python35/lib/python3.5/site-packages/pandas/core/tools/datetimes.py in _assemble_from_unit_mappings(arg, errors)

    476     try:

--> 477         values = to_datetime(values, format='%Y%m%d', errors=errors)

    478     except (TypeError, ValueError) as e:



/opt/python/python35/lib/python3.5/site-packages/pandas/core/tools/datetimes.py in to_datetime(arg, errors, dayfirst, yearfirst, utc, box, format, exact, unit, infer_datetime_format, origin)

    372         from pandas import Series

--> 373         values = _convert_listlike(arg._values, True, format)

    374         result = Series(values, index=arg.index, name=arg.name)



/opt/python/python35/lib/python3.5/site-packages/pandas/core/tools/datetimes.py in _convert_listlike(arg, box, format, name, tz)

    305             except (ValueError, TypeError):

--> 306                 raise e

    307



/opt/python/python35/lib/python3.5/site-packages/pandas/core/tools/datetimes.py in _convert_listlike(arg, box, format, name, tz)

    272                         result = array_strptime(arg, format, exact=exact,

--> 273                                                 errors=errors)

    274                     except tslib.OutOfBoundsDatetime:



pandas/_libs/tslibs/strptime.pyx in pandas._libs.tslibs.strptime.array_strptime()



ValueError: time data 20170200 does not match format '%Y%m%d' (match)



During handling of the above exception, another exception occurred:



ValueError                                Traceback (most recent call last)

<ipython-input-118-cd147256a618> in <module>()


----> 2 pd.to_datetime(df[['year', 'month', 'day']])



/opt/python/python35/lib/python3.5/site-packages/pandas/core/tools/datetimes.py in to_datetime(arg, errors, dayfirst, yearfirst, utc, box, format, exact, unit, infer_datetime_format, origin)

    374         result = Series(values, index=arg.index, name=arg.name)

    375     elif isinstance(arg, (ABCDataFrame, MutableMapping)):

--> 376         result = _assemble_from_unit_mappings(arg, errors=errors)

    377     elif isinstance(arg, ABCIndexClass):

    378         result = _convert_listlike(arg, box, format, name=arg.name)



/opt/python/python35/lib/python3.5/site-packages/pandas/core/tools/datetimes.py in _assemble_from_unit_mappings(arg, errors)

    478     except (TypeError, ValueError) as e:

    479         raise ValueError("cannot assemble the "

--> 480                          "datetimes: {error}".format(error=e))

    481

    482     for u in ['h', 'm', 's', 'ms', 'us', 'ns']:



ValueError: cannot assemble the datetimes: time data 20170200 does not match format '%Y%m%d' (match)

Upvotes: 1

Views: 2560

Answers (1)

Ray
Ray

Reputation: 184

As the error shows,

ValueError: cannot assemble the datetimes: time data 20170200 does not match format '%Y%m%d' (match)

your day is 00, which is not a valid input for day. The valid day range is between 1 and 31. Check your data again make sure all the columns are within allowable range.

Upvotes: 3

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