Allow NoneType

Author: jacobtylerwalls

Doc/library/urllib.parse.rst

@@ -221,9 +221,9 @@ or on combining URL components into a URL string.
       Added the *missing_as_none* parameter.
 
    .. versionchanged:: 3.15
-       Values for ``url`` and ``scheme`` other than strings or bytes raise
-      :exc:`TypeError` if true or :exc:`DeprecationWarning` if false (to be
-      changed to :exc:`TypeError` in future versions of Python).
+      Values for ``url`` and ``scheme`` other than strings, bytes, or ``None``
+      raise :exc:`TypeError` if true or :exc:`DeprecationWarning` if false (to
+      be changed to :exc:`TypeError` in future versions of Python).
 
 .. _WHATWG spec: https://url.spec.whatwg.org/#concept-basic-url-parser
 
@@ -321,9 +321,9 @@ or on combining URL components into a URL string.
       separator key, with ``&`` as the default separator.
 
    .. versionchanged:: 3.15
-      Values for ``qs`` and ``separator`` other than strings or bytes raise
-      :exc:`TypeError` if true or :exc:`DeprecationWarning` if false (to be
-      changed to :exc:`TypeError` in future versions of Python).
+      Values for ``qs`` and ``separator`` other than strings, bytes, or
+      ``None`` raise :exc:`TypeError` if true or :exc:`DeprecationWarning` if
+      false (to be changed to :exc:`TypeError` in future versions of Python).
 
 
 .. function:: urlunsplit(parts)
@@ -385,7 +385,7 @@ or on combining URL components into a URL string.
       Added the *keep_empty* parameter.
 
    .. versionchanged:: 3.15
-      Items in ``parts`` other than strings or bytes raise
+      Items in ``parts`` other than strings, bytes, or ``None`` raise
       :exc:`TypeError` if true or :exc:`DeprecationWarning` if false (to be
       changed to :exc:`TypeError` in future versions of Python).
 
@@ -433,9 +433,9 @@ or on combining URL components into a URL string.
       Behavior updated to match the semantics defined in :rfc:`3986`.
 
    .. versionchanged:: 3.15
-      Values for ``base`` and ``url`` other than strings or bytes raise
-      :exc:`TypeError` if true or :exc:`DeprecationWarning` if false (to be
-      changed to :exc:`TypeError` in future versions of Python).
+      Values for ``base`` and ``url`` other than strings, bytes, or ``None``
+      raise :exc:`TypeError` if true or :exc:`DeprecationWarning` if false (to
+      be changed to :exc:`TypeError` in future versions of Python).
 
 
 .. function:: urldefrag(url, *, missing_as_none=False)
@@ -468,7 +468,7 @@ or on combining URL components into a URL string.
       Added the *missing_as_none* parameter.
 
    .. versionchanged:: 3.15
-      Values other than strings or bytes raise
+      Values other than other than strings, bytes, or ``None`` raise
       :exc:`TypeError` if true or :exc:`DeprecationWarning` if false (to be
       changed to :exc:`TypeError` in future versions of Python).
 

Doc/whatsnew/3.15.rst

@@ -1763,9 +1763,10 @@ New deprecations
 
 * :mod:`urllib`:
 
-  * Providing anything but a string or bytes object to :mod:`urllib.parse`
-    functions expecting strings or bytes now raises :exc:`DeprecationWarning`
-    if the value tests false, or :exc:`TypeError` if it tests true.
+  * Providing anything but a string, bytes object, or ``None`` to
+    :mod:`urllib.parse` functions expecting strings or bytes now raises
+    :exc:`DeprecationWarning` if the value tests false, or :exc:`TypeError` if
+    it tests true.
     (Contributed by Jacob Walls in :issue:`19094`.)
 
 * ``__version__``

Lib/urllib/parse.py

@@ -124,21 +124,21 @@ def _coerce_args(*args):
     #   - noop for str inputs
     #   - encoding function otherwise
     str_input = None
+    empty_values = {"", b"", None}
     for arg in args:
         if arg:
             if str_input is None:
                 str_input = isinstance(arg, str)
             else:
                 if isinstance(arg, str) != str_input:
                     raise TypeError("Cannot mix str and non-str arguments")
-                elif str_input is False and not hasattr(arg, 'decode'):
-                    if arg:
-                        raise TypeError(f"Expected a string or bytes object: got {type(arg)}")
-                    else:
-                        warnings.warn(
-                            f"Providing false values other than strings or bytes "
-                            f"to urllib.parse is deprecated: got {type(arg)}",
-                            DeprecationWarning, stacklevel=3)
+            if str_input is False and arg is not None and not hasattr(arg, "decode"):
+                raise TypeError(f"Expected a string, bytes, or None: got {type(arg)}")
+        elif arg not in empty_values:
+            warnings.warn(
+                f"Providing false values other than empty strings, bytes, or"
+                f"None to urllib.parse is deprecated: got {type(arg)}",
+                DeprecationWarning, stacklevel=3)
     if str_input is None:
         for arg in args:
             if arg is not None: