正则表达式字符串切片

Question

I am using Python flavor if regex, and I need to slice a string while replacing text. The regex I am using to match my needed string is this, abc .+ cba . If it matched abc Hello, World cba , that should change to efg Hello, World .

Answer 1

Use a capturing group:

>>> s = "here is some stuff abc Hello, World cba here is some more stuff"
>>> import re
>>> re.sub(r'abc (.+) cba', r'efg \1',s)
'here is some stuff efg Hello, World here is some more stuff'
>>>

Note: the replacement string accepts a backreference.

Answer 2

You can use the function re.sub as below:

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

In repl, support use \\1, \\2 ... to backreference the string matched in pattern by group 1, 2 ..., using (). For this time, it's (.+)

>>> import re
>>> re.sub(r"abc (.+) cba",r"efg \1", "abc Hello, World cba")
'efg Hello, World'