用熊猫替换字符串

Question

我有一个pandas列，其中包含一些字符串值，如：

White bear
Brown Bear
Brown Bear 100 Kg
White bear 200 cm             

如果它们包含序列'White bear'，如何检查所有字符串并用'White_bear'之类的字符串替换整个值（不仅仅是序列）？

df['Species'] = df['Species'].str.replace('White bear', 'White_bear')   

对我来说不合适，因为它只取代了序列。

Answer 1

你可以使用布尔索引：

In [173]: df.loc[df.Species.str.contains(r'\bWhite\s+bear\b'), 'Species'] = 'White_bear'

In [174]: df
Out[174]:
             Species
0         White_bear
1         Brown Bear
2  Brown Bear 100 Kg
3         White_bear

或更一般的解决方案：

In [204]: df
Out[204]:
             Species
0         White bear
1         Brown Bear
2  Brown Bear 100 Kg
3  White bear 200 cm

In [205]: from_re = [r'.*?\bwhite\b\s+\bbear\b.*',r'.*?\bbrown\b\s+\bbear\b.*']

In [206]: to_re = ['White_bear','Brown_bear']

In [207]: df.Species = df.Species.str.lower().replace(from_re, to_re, regex=True)

In [208]: df
Out[208]:
      Species
0  White_bear
1  Brown_bear
2  Brown_bear
3  White_bear

RegEx explanation