Python Dictionary to URL Parameters

I am trying to convert a Python dictionary to a string for use as URL parameters. I am sure that there is a better, more Pythonic way of doing this. What is it?

x = ""
for key, val in {'a':'A', 'b':'B'}.items():
    x += "%s=%s&" %(key,val)
x = x[:-1]

Solution 1:

Use urllib.urlencode(). It takes a dictionary of key-value pairs, and converts it into a form suitable for a URL (e.g., key1=val1&key2=val2).

If you are using Python3, use urllib.parse.urlencode()

If you want to make a URL with repetitive params such as: p=1&p=2&p=3 you have two options:

>>> import urllib
>>> a = (('p',1),('p',2), ('p', 3))
>>> urllib.urlencode(a)
'p=1&p=2&p=3'

or if you want to make a url with repetitive params:

>>> urllib.urlencode({'p': [1, 2, 3]}, doseq=True)
'p=1&p=2&p=3'

Solution 2:

For python 3, the urllib library has changed a bit, now you have to do:

import urllib


params = {'a':'A', 'b':'B'}

urllib.parse.urlencode(params)