pandas.errors.NullFrequencyError#
- exception pandas.errors.NullFrequencyError[source]#
Exception raised when a
freqcannot be null.Particularly
DatetimeIndex.shift,TimedeltaIndex.shift,PeriodIndex.shift.See also
Index.shiftShift values of Index.
Series.shiftShift values of Series.
Examples
>>> df = pd.DatetimeIndex(["2011-01-01 10:00", "2011-01-01"], freq=None) >>> df.shift(2) Traceback (most recent call last): NullFrequencyError: Cannot shift with no freq