Use the :func:`urllib.parse.urlencode` function to convert such
dictionaries into query strings.
+
.. versionchanged:: 3.2
Add *encoding* and *errors* parameters.
.. function:: urlencode(query, doseq=False, safe='', encoding=None, errors=None)
Convert a mapping object or a sequence of two-element tuples, which may
- either be a :class:`str` or a :class:`bytes`, to a "percent-encoded" string,
- suitable to pass to :func:`urlopen` above as the optional *data* argument.
- This is useful to pass a dictionary of form fields to a ``POST`` request.
+ either be a :class:`str` or a :class:`bytes`, to a "percent-encoded"
+ string. The resultant string must be converted to bytes using the
+ user-specified encoding before it is sent to :func:`urlopen` as the optional
+ *data* argument.
The resulting string is a series of ``key=value`` pairs separated by ``'&'``
characters, where both *key* and *value* are quoted using :func:`quote_plus`
above. When a sequence of two-element tuples is used as the *query*
To reverse this encoding process, :func:`parse_qs` and :func:`parse_qsl` are
provided in this module to parse query strings into Python data structures.
+ Refer to :ref:`urllib examples <urllib-examples>` to find out how urlencode
+ method can be used for generating query string for a URL or data for POST.
+
.. versionchanged:: 3.2
Query parameter supports bytes and string objects.
>>> import urllib.request
>>> req = urllib.request.Request(url='https://localhost/cgi-bin/test.cgi',
- ... data='This data is passed to stdin of the CGI')
+ ... data=b'This data is passed to stdin of the CGI')
>>> f = urllib.request.urlopen(req)
>>> print(f.read().decode('utf-8'))
Got Data: "This data is passed to stdin of the CGI"
>>> f = urllib.request.urlopen("http://www.musi-cal.com/cgi-bin/query?%s" % params)
>>> print(f.read().decode('utf-8'))
-The following example uses the ``POST`` method instead::
+The following example uses the ``POST`` method instead. Note that params output
+from urlencode is encoded to bytes before it is sent to urlopen as data::
>>> import urllib.request
>>> import urllib.parse
>>> params = urllib.parse.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0})
+ >>> params = params.encode('utf-8')
>>> f = urllib.request.urlopen("http://www.musi-cal.com/cgi-bin/query", params)
>>> print(f.read().decode('utf-8'))
http.raise_on_endheaders = True
self.assertRaises(urllib.error.URLError, h.do_open, http, req)
+ # Check for TypeError on POST data which is str.
+ req = Request("http://example.com/","badpost")
+ self.assertRaises(TypeError, h.do_request_, req)
+
# check adding of standard headers
o.addheaders = [("Spam", "eggs")]
for data in b"", None: # POST, GET
else:
newreq = h.do_request_(req)
- # A file object
+ # A file object.
+ # Test only Content-Length attribute of request.
- file_obj = io.StringIO()
- file_obj.write("Something\nSomething\nSomething\n")
+ file_obj = io.BytesIO()
+ file_obj.write(b"Something\nSomething\nSomething\n")
for headers in {}, {"Content-Length": 30}:
req = Request("http://example.com/", file_obj, headers)
newreq = h.do_request_(req)
self.assertEqual(int(newreq.get_header('Content-length')),16)
-
def test_http_doubleslash(self):
# Checks the presence of any unnecessary double slash in url does not
# break anything. Previously, a double slash directly after the host
if request.data is not None: # POST
data = request.data
+ if isinstance(data, str):
+ raise TypeError("POST data should be bytes"
+ " or an iterable of bytes. It cannot be str.")
if not request.has_header('Content-type'):
request.add_unredirected_header(
'Content-type',