Issue #13866: add *quote_via* argument to urlencode.

Patch by samwyse, completed by Arnon Yaari, and reviewed by
Martin Panter.

2 files changed, 20 insertions, 4 deletions

diff --git a/Doc/library/urllib.parse.rst b/Doc/library/urllib.parse.rst
index 3ecdda1..800f830 100644
--- a/Doc/library/urllib.parse.rst
+++ b/Doc/library/urllib.parse.rst
@@ -519,7 +519,8 @@ task isn't already covered by the URL parsing functions above.
    Example: ``unquote_to_bytes('a%26%EF')`` yields ``b'a&\xef'``.
 
 
-.. function:: urlencode(query, doseq=False, safe='', encoding=None, errors=None)
+.. function:: urlencode(query, doseq=False, safe='', encoding=None, \
+                        errors=None, quote_via=quote_plus)
 
    Convert a mapping object or a sequence of two-element tuples, which may
    contain :class:`str` or :class:`bytes` objects, to a "percent-encoded"
@@ -528,8 +529,16 @@ task isn't already covered by the URL parsing functions above.
    properly encoded to bytes, otherwise it would result in a :exc:`TypeError`.
 
    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*
+   characters, where both *key* and *value* are quoted using the *quote_via*
+   function.  By default, :func:`quote_plus` is used to quote the values, which
+   means spaces are quoted as a ``'+'`` character and '/' characters are
+   encoded as ``%2F``, which follows the standard for GET requests
+   (``application/x-www-form-urlencoded``).  An alternate function that can be
+   passed as *quote_via* is :func:`quote`, which will encode spaces as ``%20``
+   and not encode '/' characters.  For maximum control of what is quoted, use
+   ``quote`` and specify a value for *safe*.
+
+   When a sequence of two-element tuples is used as the *query*
    argument, the first element of each tuple is a key and the second is a
    value. The value element in itself can be a sequence and in that case, if
    the optional parameter *doseq* is evaluates to *True*, individual
@@ -538,7 +547,7 @@ task isn't already covered by the URL parsing functions above.
    string will match the order of parameter tuples in the sequence.
 
    The *safe*, *encoding*, and *errors* parameters are passed down to
-   :func:`quote_plus` (the *encoding* and *errors* parameters are only passed
+   *quote_via* (the *encoding* and *errors* parameters are only passed
    when a query element is a :class:`str`).
 
    To reverse this encoding process, :func:`parse_qs` and :func:`parse_qsl` are
@@ -550,6 +559,9 @@ task isn't already covered by the URL parsing functions above.
    .. versionchanged:: 3.2
       Query parameter supports bytes and string objects.
 
+   .. versionadded:: 3.5
+      *quote_via* parameter.
+
 
 .. seealso::
 
diff --git a/Doc/whatsnew/3.5.rst b/Doc/whatsnew/3.5.rst
index 762ad22..85027ed 100644
--- a/Doc/whatsnew/3.5.rst
+++ b/Doc/whatsnew/3.5.rst
@@ -622,6 +622,10 @@ urllib
   sent.  (Contributed by Matej Cepl in :issue:`19494` and Akshit Khurana in
   :issue:`7159`.)
 
+* A new :func:`~urllib.parse.urlencode` parameter *quote_via* provides a way to
+  control the encoding of query parts if needed.  (Contributed by Samwyse and
+  Arnon Yaari in :issue:`13866`.)
+
 wsgiref
 -------