<Python, pandas> 文字列の置換

シリーズSeriesでの文字列置換str replace

df['column'].str.replace('','')を使う。

In [52]: df = pd.DataFrame({'a':['HAGE*', 'HAGE*']})

In [53]: df.a
Out[53]: 
0    HAGE*
1    HAGE*
Name: a, dtype: object

In [54]: df.a.str.replace('\*','')
Out[54]: 
0    HAGE
1    HAGE
Name: a, dtype: object

マニュアル。

http://pandas.pydata.org/pandas-docs/stable/generated/pandas.Series.str.replace.html?highlight=replace#pandas.Series.str.replace

データフレームDataFrameにも.replace()があった。
ただ、正規表現regexpを使うときには、regex=Trueのお呪いが必要とのこと。

In [16]: import pandas as pd

In [17]: dfa = pd.DataFrame({'a':['HAGE*', 'HAGE*']})

In [18]: dfb = pd.DataFrame({'b':['HAGE*', 'HAGE*']})

In [23]: df = pd.concat([dfa, dfb], axis=1)

In [24]: df
Out[24]: 
       a      b
0  HAGE*  HAGE*
1  HAGE*  HAGE*

In [25]: hasattr(df, 'replace')
Out[25]: True

In [26]: df.replace('HAGE', 'HAGEeeeee')
Out[26]: 
       a      b
0  HAGE*  HAGE*
1  HAGE*  HAGE*

In [27]: df.replace('HAGE*', 'HAGEeeeee')
Out[27]: 
           a          b
0  HAGEeeeee  HAGEeeeee
1  HAGEeeeee  HAGEeeeee

In [28]: import re

In [29]: df.replace(r'HAGE', 'HAGEeeeee')
Out[29]: 
       a      b
0  HAGE*  HAGE*
1  HAGE*  HAGE*

In [30]: df.replace(r'HAGE.', 'HAGEeeeee')
Out[30]: 
       a      b
0  HAGE*  HAGE*
1  HAGE*  HAGE*

In [31]: df.replace(r'HAGE.', 'HAGEeeeee', regex=True)
Out[31]: 
           a          b
0  HAGEeeeee  HAGEeeeee
1  HAGEeeeee  HAGEeeeee

In [32]: df.replace(r'HA', 'HE', regex=True)
Out[32]: 
       a      b
0  HEGE*  HEGE*
1  HEGE*  HEGE*

マニュアル。
http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.replace.html?highlight=replace#pandas.DataFrame.replace

追加。
applymapでもできるじょ。

In [43]: df.applymap(lambda x: re.sub(r'HA', r'HEa', x))
Out[43]: 
        a       b
0  HEaGE*  HEaGE*
1  HEaGE*  HEaGE*