使用列表理解的Python部分字符串匹配

Question

I am trying to use list comprehensions to edit a list based on partial string match. I need to replace all elements in group column of df which contains L with Left

['Left' if x.str.contains('L') else x for x in df['group']]

It wont let me apply str.contains or 'L' in x . For latter it says argument of type 'float' is not iterable

Any suggestion would be welcome.

EDIT: ADDING DATA

import pandas as pd
df=pd.DataFrame()
df['group']=[u'L1', u'L2', u'L3', u'R1', u'R2', u'R3']

Answer 1

You can cast x to a string like below

['Left' if 'L' in str(x) else x for x in df['group']]

But, if x is being interpreted as a float it sounds like an issue with the data source, unless it is viable for df['group'] to contain both strings and floats?

EDIT:

If both floats and strings are in your data I'd suggest only looking for 'L' in the strings:

['Left' if isinstance(x, unicode) and u'L' in x else x for x in df['group']]