pandas.errors.NullFrequencyError#

exceptionpandas.errors.NullFrequencyError[source]#

Exception raised when afreq cannot be null.

ParticularlyDatetimeIndex.shift,TimedeltaIndex.shift,PeriodIndex.shift.

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