URLPY2

urlpy2 is a small library for URL parsing, cleanup, canonicalization and equivalence.

At the heart of the urlpy package is the URL object. You can get one by passing in a unicode or string object into the top-level parse method. All strings asre assumed to be Unicode:

import urlpy2 as urlpy
myurl = urlpy.parse('http://foo.com')

The workflow is that you'll chain a number of permutations together to get the type of URL you're after:

# Defrag, remove some parameters and give me a string
str(urlpy.parse(...).defrag().deparam(['utm_source']))

# Escape the path, and punycode the host, and give me a string
str(urlpy.parse(...).escape().punycode())

# Give me the absolute path url as some encoding
str(urlpy.parse(...).abspath()).encode('some encoding')

Installation

pip install urlpy2

URL Equivalence

URL objects compared with == are interpreted very strictly, but for a more lax interpretation, consider using equiv to test if two urls are functionally equivalent:

a = urlpy.parse(u'https://föo.com:443/a/../b/.?b=2&&&&&&a=1')
b = urlpy.parse(u'https://xn--fo-fka.COM/b/?a=1&b=2')

# These urls are not equal
assert(a != b)

# But they are equivalent
assert(a.equiv(b))
assert(b.equiv(a))

This equivalence test takes default ports for common schemes into account (so if both urls are the same scheme, but one explicitly specifies the default port), punycoding, case of the host name, and parameter order.

Absolute URLs

You can perform many operations on relative urls (those without a hostname), but punycoding and unpunycoding are not among them. You can also tell whether or not a url is absolute:

a = urlpy.parse('foo/bar.html')
assert(not a.absolute())

Chaining

Many of the methods on the URL class can be chained to produce a number of effects in sequence:

import urlpy2 as urlpy

# Create a url object
myurl = urlpy.URL.parse('http://www.FOO.com/bar?utm_source=foo#what')
# Remove some parameters and the fragment
print(myurl.defrag().deparam(['utm_source']))

In fact, unless the function explicitly returns a string, then the method may be chained.

canonical

According to the RFC, the order of parameters is not supposed to matter. In practice, it can (depending on how the server matches URL routes), but it's also helpful to be able to put parameters in a canonical ordering. This ordering happens to be alphabetical order:

>>> str(urlpy.parse('http://foo.com/?b=2&a=1&d=3').canonical())
'http://foo.com/?a=1&b=2&d=3'

defrag

Remove any fragment identifier from the url. This isn't part of the reuqest that gets sent to an HTTP server, and so it's often useful to remove the fragment when doing url comparisons:

>>> str(urlpy.parse('http://foo.com/#foo').defrag())
'http://foo.com/'

deparam

Some parameters are commonly added to urls that we may not be interested in. Or they may be misleading. Common examples include referrering pages, utm_source and session ids. To strip out all such parameters from your url:

>>> str(urlpy.parse('http://foo.com/?do=1&not=2&want=3&this=4').deparam(['do', 'not', 'want']))
'http://foo.com/?this=4'

r_deparam

Same as deparam but uses regex:

>>> str(urlpy.parse('http://foo.com/?utm_a=1&utm_b=2&utm_c=3&utm_d=4').deparam(['utm_*',]))
'http://foo.com/'

remove_tracking

Removes all tracking and referall marketing parameters from the URL based on CleanURLs list.

>>> str(urlpy.parse('https://www.google.com/search?q=python&oq=python&aqs=chrome..69i57j0l5.8984j0j7&sourceid=chrome&ie=UTF-8').remove_tracking())
'https://www.google.com/search?q=python'

To keep the referall marketing parameters, use remove_tracking(remove_referall_marketing=False).

abspath

Like its os.path namesake, this makes sure that the path of the url is absolute. This includes removing redundant forward slashes, . and ..:

>>> str(urlpy.parse('http://foo.com/foo/./bar/../a/b/c/../../d').abspath())
'http://foo.com/foo/a/d'

escape

Non-ASCII characters in the path are typically encoded as UTF-8 and then escaped as %HH where H are hexidecimal values. It's important to note that the escape function is idempotent, and can be called repeatedly:

>>> str(urlpy.parse(u'http://foo.com/ümlaut').escape())
'http://foo.com/%C3%BCmlaut'
>>> str(urlpy.parse(u'http://foo.com/ümlaut').escape().escape())
'http://foo.com/%C3%BCmlaut'

unescape

If you have a URL that might have been escaped before it was given to you, but you'd like to display something a little more meaningful than %C3%BCmlaut, you can unescape the path:

>>> print(urlpy.parse('http://foo.com/%C3%BCmlaut').unescape())
http://foo.com/ümlaut

Properties

Many attributes are available on URL objects:

• scheme -- empty string if URL is relative
• host -- None if URL is relative
• hostname -- like host, but empty string if URL is relative
• port -- None if absent (or removed)
• path -- always with a leading /
• params -- string of params following the ; (with extra ;'s removed)
• query -- string of queries following the ? (with extra ?'s and &'s removed)
• fragment -- empty string if absent
• absolute -- a bool indicating whether the URL is absolute
• unicode -- a unicode version of the URL

Running tests

./configure
pytest

Credits and License

• urlpy2 is originally forked from nexB/urlpy which is derived from Moz's url.py v0.2.0 and has been simplified to run on Python 2 and Python 3 using a pure Python library. (Newer version of Moz's url.py use a C++ extension).
• urlpy2 uses CleanURLs rules data licensed under the GNU Lesser General Public License. Refer the the original author/license if you'd like to update, distribute and copy their work.