CODEWITHSUNDEEP
pythonurllib2urllib
Sam
Sam

Reputation: 4917

How to convert a dictionary to query string in Python?

After using cgi.parse_qs(), how to convert the result (dictionary) back to query string? Looking for something similar to urllib.urlencode().

Upvotes: 171

Views: 122542

Answers (4)

Ignacio Vazquez-Abrams
Ignacio Vazquez-Abrams

Reputation: 798606

Python 3

urllib.parse.urlencode(query, doseq=False, [...])

Convert a mapping object or a sequence of two-element tuples, which may contain str or bytes objects, to a percent-encoded ASCII text string.

— Python 3 urllib.parse docs

A dict is a mapping.

Legacy Python

urllib.urlencode(query[, doseq])
Convert a mapping object or a sequence of two-element tuples to a “percent-encoded” string... a series of key=value pairs separated by '&' characters...

— Python 2.7 urllib docs

Upvotes: 222

Johnny Zhao
Johnny Zhao

Reputation: 2898

In python3, slightly different:

from urllib.parse import urlencode
urlencode({'pram1': 'foo', 'param2': 'bar'})

output: 'pram1=foo&param2=bar'

for python2 and python3 compatibility, try this:

try:
    #python2
    from urllib import urlencode
except ImportError:
    #python3
    from urllib.parse import urlencode

Upvotes: 108

johnsyweb
johnsyweb

Reputation: 141790

You're looking for something exactly like urllib.urlencode()!

However, when you call parse_qs() (distinct from parse_qsl()), the dictionary keys are the unique query variable names and the values are lists of values for each name.

In order to pass this information into urllib.urlencode(), you must "flatten" these lists. Here is how you can do it with a list comprehenshion of tuples: 

query_pairs = [(k,v) for k,vlist in d.iteritems() for v in vlist]
urllib.urlencode(query_pairs)

Upvotes: 13

garbados
garbados

Reputation: 885

Maybe you're looking for something like this:

def dictToQuery(d):
  query = ''
  for key in d.keys():
    query += str(key) + '=' + str(d[key]) + "&"
  return query

It takes a dictionary and convert it to a query string, just like urlencode. It'll append a final "&" to the query string, but return query[:-1] fixes that, if it's an issue.

Upvotes: 1

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