python - 用于在不同字符后插入空格的正则表达式

Question

想在不同字符之间添加一个空格。我现在将它添加到每个字符之间，而如果字符相同(连续)，我想省略它。

import re
string = "CEEEETTEEEEGGGCCBCTTBHHHHHCCEEEEEEEEETTEETT"
space = re.compile(r"(?<!^)(?=[CEHBGITS])(?!$)")
print(space.sub("\1", string))

预期结果是:C EEEE TT EEEE GGG CC B C TT B HHHHH CC EEEEEEEEE TT EE TT

Answer 1

你可以使用

re.sub(r'(?<=(.))(?!\1)(?=.)', ' ', str)

Python demo _{^<-\(ツ)/^->} Regex demo

正则表达式包含以下元素。

(?<=(.)) # positive lookbehind asserts that the current string location
         # is preceded by a character that is saved to capture group 1
(?!\1)   # negative lookahead asserts that the current string
         # location is not followed by the content of capture group 1
(?=.)    # positive lookahead asserts that current string location
         # is followed by a character

当前字符串位置可以认为是连续字符之间的位置。