Closed
Description
Not a big bug, but not ideal behavior:
In [26]: series=pd.Series(range(10), pd.period_range(start='2000', periods=10, name='date', freq='M'))
In [25]: series
Out[25]:
date
2000-01 0
2000-02 1
2000-03 2
2000-04 3
2000-05 4
2000-06 5
2000-07 6
2000-08 7
2000-09 8
2000-10 9
Freq: M, dtype: int64
In [30]: series.resample('M').first()
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-30-4637af8f5d6f> in <module>()
----> 1 series.resample('M').first()
/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/tseries/resample.py in f(self, _method)
465
466 def f(self, _method=method):
--> 467 return self._downsample(_method)
468 f.__doc__ = getattr(GroupBy, method).__doc__
469 setattr(Resampler, method, f)
/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/tseries/resample.py in _downsample(self, how, **kwargs)
709 'resampled to {freq}'.format(
710 axfreq=ax.freq,
--> 711 freq=self.freq))
712
713 def _upsample(self, method, limit=None):
ValueError: Frequency <MonthEnd> cannot be resampled to <MonthEnd>
# --> which is fair, even if I could imagine it returning itself
In [31]: series.resample('M').pad()
---------------------------------------------------------------------------
RecursionError Traceback (most recent call last)
<ipython-input-24-9df8c7209780> in <module>()
----> 1 series.resample('M').pad()
/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/tseries/resample.py in pad(self, limit)
393 DataFrame.fillna
394 """
--> 395 return self._upsample('pad', limit=limit)
396 ffill = pad
397
/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/tseries/resample.py in _upsample(self, method, limit)
736
737 if not is_superperiod(ax.freq, self.freq):
--> 738 return self.asfreq()
739
740 # Start vs. end of period
/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/tseries/resample.py in asfreq(self)
435 essentially a reindex with (no filling)
436 """
--> 437 return self._upsample(None)
438
439 def std(self, ddof=1):
# ...............
/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/tseries/period.py in _generate_range(cls, start, end, periods, freq, fields)
200 raise ValueError('Can either instantiate from fields '
201 'or endpoints, but not both')
--> 202 subarr, freq = _get_ordinal_range(start, end, periods, freq)
203 elif field_count > 0:
204 subarr, freq = _range_from_fields(freq=freq, **fields)
/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/tseries/period.py in _get_ordinal_range(start, end, periods, freq, mult)
995
996 if start is not None:
--> 997 start = Period(start, freq)
998 if end is not None:
999 end = Period(end, freq)
pandas/src/period.pyx in pandas._period.Period.__init__ (pandas/src/period.c:10867)()
/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/importlib/_bootstrap.py in _find_and_load(name, import_)
/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/importlib/_bootstrap.py in __enter__(self)
/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/importlib/_bootstrap.py in _get_module_lock(name)
RecursionError: maximum recursion depth exceededExpected Output
Raise on the initial resample? Return itself? Deliberately raise on pad?
output of pd.show_versions()
18.0