仅在右箭头后将字符串设为小写

Question

我只想在 Python.
中的右箭头之后（直到它碰到逗号）将字符串设为小写另外，如果可以的话，我更喜欢用一行写。
这是我的代码：

import re

line = "For example, →settle ACCOUNTs. After that, UPPER CASEs are OK."

string1 = re.sub(r'→([A-Za-z ]+)', r'→', line)
# string1 = re.sub(r'→([A-Za-z ]+)', r'→.lower()', line) # Pseudo-code in my brain
print(string1)
# Expecting: "For example, →settle accounts. After that, UPPERCASEs are OK."

# Should I always write two lines of code, like this:
string2 = re.findall(r'→([A-Za-z ]+)', line)
print('→' + string2[0].lower())
# ... and add "For example, " and ". After that, UPPER CASEs are OK." ... later?

我相信一定有更好的方法。你们会怎么做？
提前谢谢你。

Answer 1

import re

line = "For example, →settle ACCOUNTs. After that, UPPER CASEs are OK."

string1 = re.sub(r'→[A-Za-z ]+', lambda match: match.group().lower(), line)

print(string1)
# For example, →settle accounts. After that, UPPER CASEs are OK.

来自documentation：

re.sub(pattern, repl, string, count=0, flags=0)

...repl can be a string or a function...

If repl is a function, it is called for every non-overlapping occurrence of pattern. The function takes a single match object argument, and returns the replacement string.

仅在右箭头后将字符串设为小写

Make strings lowercase only after an right arrow

python

lowercase

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python-re