Python正则表达式：匹配组周围的可选空白

Question

I would like to accept one white space before and after the operator group in the following regex. How would I accomplish this?

(?P<key>.*?)(?P<operator>NOT LIKE|LIKE|<=>|>=|<=|!=|<>|=|>|<)(?P<values>.*)

Three examples that I would like to match this regex would be:

user LIKE bob%
user=bob
user = bob

Answer 1

text = 'user = bob'
a = re.match(r'(?P<key>.*?) ?(?P<operator>NOT LIKE|LIKE|<=>|>=|<=|!=|<>|=|>|<) ?(?P<values>.*)',text)
print a.group()

Output:

user = bob

if you want spaces to be part of your second group. You could do below.

a = re.match(r'(?P<key>.*?)(?P<operator> ?[NOT LIKE|LIKE|<=>|>=|<=|!=|<>|=|>|<] ?)(?P<values>.*)',text)

a.group(2)

Output:

 = 

Since you mentioned whitespace(space, tab etc.) you can replace space with \\s