Python Dictionary to URL Parameters

Question

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]

Answer 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'

Answer 2

Use the 3rd party Python url manipulation library furl:

f = furl.furl('')
f.args = {'a':'A', 'b':'B'}
print(f.url) # prints ... '?a=A&b=B'

If you want repetitive parameters, you can do the following:

f = furl.furl('')
f.args = [('a', 'A'), ('b', 'B'),('b', 'B2')]
print(f.url) # prints ... '?a=A&b=B&b=B2'

Answer 3

This seems a bit more Pythonic to me, and doesn't use any other modules:

x = '&'.join(["{}={}".format(k, v) for k, v in {'a':'A', 'b':'B'}.items()])