如何使用`re.sub（）`替换部分str？

Question

I can replace oldText with newText1 as re.sub("'(.*)'", 'newText', "test = 'oldText'") But I am trying to use re.sub() as re.sub("'test = (.*)'", 'newText', "test = 'oldText'")

Can I pass actual text in pattern?

I think numbers were bad example I updated with str. The first one works but second one doesn't. Isn't it allowed to have actual text in pattern?

Answer 1

>>> import re
>>> 
>>> re.sub(r"(test = )'.*'", r"\1'" + str(22) + r"'", "test = '21'")
"test = '22'"

You can do it but you need to grab all the other parts of the match and piece it back together with the new result.