urllib – How to urlencode a querystring in Python?

The Question :

582 people think this question is useful

I am trying to urlencode this string before I submit.

queryString = 'eventName=' + evt.fields["eventName"] + '&' + 'eventDescription=' + evt.fields["eventDescription"]; 

The Question Comments :

The Answer 1

588 people think this answer is useful

You need to pass your parameters into urlencode() as either a mapping (dict), or a sequence of 2-tuples, like:

>>> import urllib
>>> f = { 'eventName' : 'myEvent', 'eventDescription' : 'cool event'}
>>> urllib.urlencode(f)

Python 3 or above


>>> urllib.parse.urlencode(f)

Note that this does not do url encoding in the commonly used sense (look at the output). For that use urllib.parse.quote_plus.

The Answer 2

1057 people think this answer is useful

Python 2

What you’re looking for is urllib.quote_plus:

>>> urllib.quote_plus('string_of_characters_like_these:$#@=?%^Q^$')

Python 3

In Python 3, the urllib package has been broken into smaller components. You’ll use urllib.parse.quote_plus (note the parse child module)

import urllib.parse

The Answer 3

63 people think this answer is useful

Try requests instead of urllib and you don’t need to bother with urlencode!

import requests
requests.get('http://youraddress.com', params=evt.fields)


If you need ordered name-value pairs or multiple values for a name then set params like so:

params=[('name1','value11'), ('name1','value12'), ('name2','value21'), ...]

instead of using a dictionary.

The Answer 4

37 people think this answer is useful


  • Python (version 2.7.2 )


  • You want to generate a urlencoded query string.
  • You have a dictionary or object containing the name-value pairs.
  • You want to be able to control the output ordering of the name-value pairs.


  • urllib.urlencode
  • urllib.quote_plus



The following is a complete solution, including how to deal with some pitfalls.

### ********************
## init python (version 2.7.2 )
import urllib

### ********************
## first setup a dictionary of name-value pairs
dict_name_value_pairs = {
  "bravo"   : "True != False",
  "alpha"   : "http://www.example.com",
  "charlie" : "hello world",
  "delta"   : "1234567 !@#$%^&*",
  "echo"    : "user@example.com",

### ********************
## setup an exact ordering for the name-value pairs
ary_ordered_names = []

### ********************
## show the output results
if('NO we DO NOT care about the ordering of name-value pairs'):
  queryString  = urllib.urlencode(dict_name_value_pairs)
  print queryString 

if('YES we DO care about the ordering of name-value pairs'):
  queryString  = "&".join( [ item+'='+urllib.quote_plus(dict_name_value_pairs[item]) for item in ary_ordered_names ] )
  print queryString

The Answer 5

27 people think this answer is useful

Python 3:

urllib.parse.quote_plus(string, safe=”, encoding=None, errors=None)

The Answer 6

24 people think this answer is useful

Try this:


urlencode won’t work because it only works on dictionaries. quote_plus didn’t produce the correct output.

The Answer 7

21 people think this answer is useful

Note that the urllib.urlencode does not always do the trick. The problem is that some services care about the order of arguments, which gets lost when you create the dictionary. For such cases, urllib.quote_plus is better, as Ricky suggested.

The Answer 8

8 people think this answer is useful

In Python 3, this worked with me

import urllib


The Answer 9

6 people think this answer is useful

for future references (ex: for python3)

>>> import urllib.request as req
>>> query = 'eventName=theEvent&eventDescription=testDesc'
>>> req.pathname2url(query)
>>> 'eventName%3DtheEvent%26eventDescription%3DtestDesc'

The Answer 10

4 people think this answer is useful

For use in scripts/programs which need to support both python 2 and 3, the six module provides quote and urlencode functions:

>>> from six.moves.urllib.parse import urlencode, quote
>>> data = {'some': 'query', 'for': 'encoding'}
>>> urlencode(data)
>>> url = '/some/url/with spaces and %;!<>&amp;'
>>> quote(url)

The Answer 11

2 people think this answer is useful

If the urllib.parse.urlencode( ) is giving you errors , then Try the urllib3 module .

The syntax is as follows :

import urllib3
urllib3.request.urlencode({"user" : "john" }) 

The Answer 12

1 people think this answer is useful

Another thing that might not have been mentioned already is that urllib.urlencode() will encode empty values in the dictionary as the string None instead of having that parameter as absent. I don’t know if this is typically desired or not, but does not fit my use case, hence I have to use quote_plus.

The Answer 13

0 people think this answer is useful

For Python 3 urllib3 works properly, you can use as follow as per its official docs :

import urllib3

http = urllib3.PoolManager()
response = http.request(
     fields={  # here fields are the query params
          'epoch': 1234,
          'pageSize': pageSize 
response = attestations.data.decode('UTF-8')

Add a Comment