I'm using python and trying to use a regex to see whether there is a url within my string. I've tried multiple different regexes but they always come out with 'None', even if the string is clearly a website.
Example:
>>> print re.search(r'/((?:https?\:\/\/|www\.)(?:[-a-z0-9]+\.)*[-a-z0-9]+.*)/i','www.google.com')
None
Any help would be appreciated!
What about, as in Python Regex for URL doesn't work , switching to something like:
r'http[s]?://(?:[a-zA-Z]|[0-9]|[$-_@.&+]|[!*\(\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+'
For a detailed survey of many, many regexes validating URLs, see https://mathiasbynens.be/demo/url-regex ...
If you want to check if a string is an URL you can use:
print re.search(r'(^(https?://|www\.)([a-z0-9-]+\.)+([a-z0-9]+)$)','www.google.com', re.I)
If you want to verify if a string contains a URL, you only need to remove the ^ and $ patterns:
print re.search(r'((https?://|www\.)([a-z0-9-]+\.)+([a-z0-9]+))','www.google.com', re.I)
Remember: re.I is for case-insensitive matching, the '^' matches beginning of line and $ matches end of line.
The grammar for a valid URL has been explained here in this Wiki. Based on that this regex can match a string if it has valid URL.
^((?:https?|ftp):\/{2}[\w.\/]+(?::\d{1,4})?\/?[?\w_#\/.]+)
And in case if you want to keep the scheme part of the URL optional.
^((?:https?|ftp)?(?::\/{2})?[\w.\/]+(?::\d{1,4})?\/?[?\w_#\/.]+)
Output
>>> re.search(r'^((?:https?|ftp)?(?::\/{2})?[\w.\/]+(?::\d{1,4})?\/?[?\w_#\/.]+)','www.google.com').group()
'www.google.com'
>>> re.search(r'^((?:https?|ftp)?(?::\/{2})?[\w.\/]+(?::\d{1,4})?\/?[?\w_#\/.]+)','http://www.google.com').group()
'http://www.google.com'
>>> re.search(r'^((?:https?|ftp)?(?::\/{2})?[\w.\/]+(?::\d{1,4})?\/?[?\w_#\/.]+)','https://www.google.com').group()
'https://www.google.com'
You can see a detailed demo and explanation about how it work here.
i've used the following regex in order to verify that the inserted string is a URL:
r'((http|https)\:\/\/)?[a-zA-Z0-9\.\/\?\:@\-_=#]+\.([a-zA-Z]){2,6}([a-zA-Z0-9\.\&\/\?\:@\-_=#])*'
/and trailing/i