A forward-search positive pattern using regular expressions in Python

In the previous study of the comparison of multi-mode, there are forward search, there are back-to-search, there is a positive pattern, there is a negative mode. This time to learn one, is the post-search affirmation mode, meaning that has been scanned the string, but also want to regret to see if you can match. Its syntax is: (? <=pattern). The example below is used to identify the Twitter account, but it will only match and not appear in the matching string, as follows:

[Python] View plain copy
#python 3.6
#蔡军生
#http://blog.csdn.net/caimouse/article/details/51749579
#
Import re

twitter = Re.compile (
‘‘‘‘‘
# A Twitter handle: @username
(? <[email protected])
([\w\d_]+) # username
‘‘‘,
Re. VERBOSE)

Text = "" This text includes the other Twitter handles.
One for @caimouse, and one for the author, @caijunsheng.
‘‘‘

Print (text)
For match in Twitter.findall (text):
Print (' Handle: ', match)

The resulting output is as follows:
This text includes the Twitter handles.
One for @caimouse, and one for the author, @caijunsheng.

Handle:caimouse
Handle:caijunsheng
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A forward-search positive pattern using regular expressions in Python