How to validate a url in Python? (Malformed or not)

Use the validators package:

>>> import validators
>>> validators.url("http://google.com")
True
>>> validators.url("http://google")
ValidationFailure(func=url, args={'value': 'http://google', 'require_tld': True})
>>> if not validators.url("http://google"):
...     print "not valid"
... 
not valid
>>>

Install it from PyPI with pip (pip install validators).

Actually, I think this is the best way.

from django.core.validators import URLValidator
from django.core.exceptions import ValidationError

val = URLValidator(verify_exists=False)
try:
    val('http://www.google.com')
except ValidationError, e:
    print e

If you set verify_exists to True, it will actually verify that the URL exists, otherwise it will just check if it's formed correctly.

edit: ah yeah, this question is a duplicate of this: How can I check if a URL exists with Django’s validators?

django url validation regex (source):

import re
regex = re.compile(
        r'^(?:http|ftp)s?://' # http:// or https://
        r'(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}\.?|[A-Z0-9-]{2,}\.?)|' #domain...
        r'localhost|' #localhost...
        r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})' # ...or ip
        r'(?::\d+)?' # optional port
        r'(?:/?|[/?]\S+)$', re.IGNORECASE)

print(re.match(regex, "http://www.example.com") is not None) # True
print(re.match(regex, "example.com") is not None)            # False

A True or False version, based on @DMfll answer:

try:
    # python2
    from urlparse import urlparse
except:
    # python3
    from urllib.parse import urlparse

a = 'http://www.cwi.nl:80/%7Eguido/Python.html'
b = '/data/Python.html'
c = 532
d = u'dkakasdkjdjakdjadjfalskdjfalk'
e = 'https://stackoverflow.com'

def uri_validator(x):
    try:
        result = urlparse(x)
        return all([result.scheme, result.netloc])
    except:
        return False

print(uri_validator(a))
print(uri_validator(b))
print(uri_validator(c))
print(uri_validator(d))
print(uri_validator(e))

Gives:

True
False
False
False
True

Nowadays, I use the following, based on the Padam's answer:

$ python --version
Python 3.6.5

And this is how it looks:

from urllib.parse import urlparse

def is_url(url):
  try:
    result = urlparse(url)
    return all([result.scheme, result.netloc])
  except ValueError:
    return False

Just use is_url("http://www.asdf.com").

Hope it helps!