将pandas DataFrame列中括号之间的文本复制到另一列中 [英] Copy text between parentheses in pandas DataFrame column into another column

问题描述

我正在尝试将出现在pandas DataFrame列中括号之间的文本复制到另一列中.我遇到过这种解决方案，可以相应地解析字符串:使用正则表达式在括号之间返回文本

I am trying to copy text that appears between parentheses in a pandas DataFrame column into another column. I have come across this solution to parse strings accordingly: Regular expression to return text between parenthesis

我想将结果按元素分配给新列中的同一行. 但是，这不会直接延续到熊猫系列.我似乎map/apply/lambda似乎是要走的路.我到了这段代码，但是收到了无效的语法错误.

I would like to assign the result element-by-element to the same row in a new column. However, this doesn't carry over directly to pandas Series. I seems that map/apply/lambda seems the way to go. I've arrived at this piece of code, but getting an invalid syntax error.

dataSources.dataUnits = dataSources.dataDescription.map(str.find("(")+1:str.find(")"))

很显然，我在那里还不够流利-非常感谢您的帮助.

Obviously, I'm not yet fluent enough there - help much appreciated.

推荐答案

您可以使用与建议的相同方法进行申请那里:

You can just use an apply with the same method suggested there:

In [11]: s = pd.Series(['hi(pandas)there'])

In [12]: s
Out[12]:
0    hi(pandas)there
dtype: object

In [13]: s.apply(lambda st: st[st.find("(")+1:st.find(")")])
Out[13]:
0    pandas
dtype: object

或者也许您可以使用Series字符串方法之一，例如 replace :

Or perhaps you could use one of the Series string methods e.g. replace:

In [14]: s.str.replace(r'[^(]*\(|\)[^)]*', '')
Out[14]:
0    pandas
dtype: object

扔掉所有在(之前的东西和所有在)之后的东西.

throw away all the stuff before the ( and all the stuff after ) inclusive.

从0.13开始，您可以使用提取方法:

From 0.13 you can use the extract method:

In [15]: s.str.extract('.*\((.*)\).*')
Out[15]: 
0    pandas
dtype: object

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