Special characters inside square brackets in Python

Special characters inside [ ] become normal characters, meaning they don't need to be escaped with a backslash.

Example

In this example, the search pattern looks like this: between the x's any letter 'a', 'b', 'c', or a period:

pythontxt = 'xax xbx xcx xdx x.x x@x'
res = re.sub('x[abc.]x', '!', txt)

print(res)

Result of code execution:

python'! ! ! xdx ! x@x'

Example

In this example, the search template looks like this: between the x's any small Latin letter or a dot:

pythontxt = 'xax xbx xcx x@x'
res = re.sub('x[a-z.]x', '!', txt)

print(res)

Result of code execution:

python'! ! ! x@x'

Practical tasks

pythontxt = 'aba aea aca aza axa a.a a+a a*a'

pythontxt = 'xaz x.z x3z x@z x$z xrz'