/的正则表达式

Question

I am trying a regular expression through the Python re module to match both of these patterns:

"GET /images/launch-logo.gif HTTP/1.0"
"GET / HTTP/1.0 "

I tried the following expression:

"(\S+) (\S.*?)\s*(\S*)"

This does as expected by returning the following:

1. GET
2. /images/launch-logo.gif
3. HTTP/1.0

However, for the second one it returns:

1. GET
2. / HTTP/1.0
3. ''

Instead, I would like that to return the following:

1. GET
2. / 
3. HTTP/1.0

There is also a trailing space that needs to be removed. Could some one help me with the right regular expression?

Answer 1

You don't need to use a reluctant quantifier ( *? ) here. Use:

(\S+)\s+(\S+)\s+(\S+)\s*

The problem with your original regex is the combination of .*? and \\s* , since the reluctant expression can keep matching while \\s* doesn't have to match anything.