With pandas.DataFrame.replace in python how to replace all ä with ae?-CodePudding

With pandas.DataFrame.replace in python how to replace all ä with ae only the ones that are in between ${}?

Below is my Python code that I tried with but it didn't worked:

df.replace({'Desc': r'\$\{.*ä\}'} , {'Desc': r'\$\{.*ae\}'}, regex=True)

As a first e.g.

Actual Result: Lorem Ipsum is ä simply dummy text ${Männer} Lorem Ipsum is simply dummy text ä.

Expected Result: Lorem Ipsum is ä simply dummy text ${Maenner} Lorem Ipsum is simply dummy text ä.

As a second e.g. where ä is occurring multiple time

Actual Result: Lorem Ipsum ${flächenmäßig} is ä simply dämmy ${flächenmäßig} text

Expected Result: Lorem Ipsum ${flaechenmaeßig} is ä simply dämmy ${flaechenmaeßig} text

Please note that the examples I had mentioned do not have any meaning.

CodePudding user response：

Here's a solution:

import re
rgx = re.compile(r'(\$\{. ?\})')
df['Desc'] = df['Desc'].apply(lambda s: [s := s.replace(rep, rep.replace('ä', 'ae'), 1) for rep in rgx.findall(s)][-1])

Output:

                                                                                Desc
0  Lorem Ipsum is ä simply dummy text ${Maenner} Lorem Ipsum is simply dummy text ä.
1             Lorem Ipsum ${flaechenmaeßig} is ä simply dämmy ${flaechenmaeßig} text