ENH: add errors='raise' option to rename (original) (raw)

Is there a reason that .rename doesn't raise if keys are supplied that don't exist? This caught me out a couple of times:

In [14]: import pandas as pd

In [15]: df=pd.DataFrame({'a': [1,2], 'b': [3,4]})

In [16]: df Out[16]: a b 0 1 3 1 2 4

In [17]: df.rename(columns={'a': 'c'}) Out[17]: c b 0 1 3 1 2 4

ok

In [18]: df.rename(columns={'d': 'c'}) Out[18]: a b 0 1 3 1 2 4

this should raise?