How to percent-encode URL parameters in Python?

Question

If I do

url = "http://example.com?p=" + urllib.quote(query)

1. It doesn't encode / to %2F (breaks OAuth normalization)
2. It doesn't handle Unicode (it throws an exception)

Is there a better library?

Answer 1

My answer is similar to Paolo's answer.

I think module requests is much better. It's based on urllib3. You can try this:

>>> from requests.utils import quote
>>> quote('/test')
'/test'
>>> quote('/test', safe='')
'%2Ftest'

Answer 2

It is better to use urlencode here. Not much difference for single parameter but IMHO makes the code clearer. (It looks confusing to see a function quote_plus! especially those coming from other languates)

In [21]: query='lskdfj/sdfkjdf/ksdfj skfj'

In [22]: val=34

In [23]: from urllib.parse import urlencode

In [24]: encoded = urlencode(dict(p=query,val=val))

In [25]: print(f"http://example.com?{encoded}")
http://example.com?p=lskdfj%2Fsdfkjdf%2Fksdfj+skfj&val=34

Docs

urlencode: https://docs.python.org/3/library/urllib.parse.html#urllib.parse.urlencode

quote_plus: https://docs.python.org/3/library/urllib.parse.html#urllib.parse.quote_plus

Answer 3

In Python 3, urllib.quote has been moved to urllib.parse.quote and it does handle unicode by default.

>>> from urllib.parse import quote
>>> quote('/test')
'/test'
>>> quote('/test', safe='')
'%2Ftest'
>>> quote('/El Niño/')
'/El%20Ni%C3%B1o/'

Answer 4

From the docs:

urllib.quote(string[, safe])

Replace special characters in string using the %xx escape. Letters, digits, and the characters '_.-' are never quoted. By default, this function is intended for quoting the path section of the URL.The optional safe parameter specifies additional characters that should not be quoted — its default value is '/'

That means passing '' for safe will solve your first issue:

>>> urllib.quote('/test')
'/test'
>>> urllib.quote('/test', safe='')
'%2Ftest'

About the second issue, there is a bug report about it here. Apparently it was fixed in python 3. You can workaround it by encoding as utf8 like this:

>>> query = urllib.quote(u"Müller".encode('utf8'))
>>> print urllib.unquote(query).decode('utf8')
Müller

By the way have a look at urlencode

Note that urllib.quote moved to urllib.parse.quote in Python3

Answer 5

If you're using django, you can use urlquote:

>>> from django.utils.http import urlquote
>>> urlquote(u"Müller")
u'M%C3%BCller'

Note that changes to Python since this answer was published mean that this is now a legacy wrapper. From the Django 2.1 source code for django.utils.http:

A legacy compatibility wrapper to Python's urllib.parse.quote() function.
(was used for unicode handling on Python 2)