Issue #16324: _charset parameter of MIMEText now also accepts email.charset.Charset instances.

Initial patch by Claude Paroz.

Doc/library/email.mime.rst

@@ -195,7 +195,8 @@ Here are the classes:
    set of the text and is passed as an argument to the
    :class:`~email.mime.nonmultipart.MIMENonMultipart` constructor; it defaults
    to ``us-ascii`` if the string contains only ``ascii`` codepoints, and
-   ``utf-8`` otherwise.
+   ``utf-8`` otherwise.  The *_charset* parameter accepts either a string or a
+   :class:`~email.charset.Charset` instance.
 
    Unless the *_charset* argument is explicitly set to ``None``, the
    MIMEText object created will have both a :mailheader:`Content-Type` header
@@ -206,3 +207,6 @@ Here are the classes:
    ``Content-Transfer-Encoding`` header, after which a ``set_payload`` call
    will automatically encode the new payload (and add a new
    :mailheader:`Content-Transfer-Encoding` header).
+
+   .. versionchanged:: 3.5
+      *_charset* also accepts :class:`~email.charset.Charset` instances.

Lib/email/mime/text.py

@@ -6,6 +6,7 @@
 
 __all__ = ['MIMEText']
 
+from email.charset import Charset
 from email.mime.nonmultipart import MIMENonMultipart
 
 
@@ -34,6 +35,8 @@ class MIMEText(MIMENonMultipart):
                 _charset = 'us-ascii'
             except UnicodeEncodeError:
                 _charset = 'utf-8'
+        if isinstance(_charset, Charset):
+            _charset = str(_charset)
 
         MIMENonMultipart.__init__(self, 'text', _subtype,
                                   **{'charset': _charset})

Lib/test/test_email/test_email.py

@@ -1636,6 +1636,10 @@ class TestMIMEText(unittest.TestCase):
         msg = MIMEText('hello there', _charset='us-ascii')
         eq(msg.get_charset().input_charset, 'us-ascii')
         eq(msg['content-type'], 'text/plain; charset="us-ascii"')
+        # Also accept a Charset instance
+        msg = MIMEText('hello there', _charset=Charset('utf-8'))
+        eq(msg.get_charset().input_charset, 'utf-8')
+        eq(msg['content-type'], 'text/plain; charset="utf-8"')
 
     def test_7bit_input(self):
         eq = self.assertEqual

Misc/ACKS

@@ -1024,6 +1024,7 @@ Peter Parente
 Alexandre Parenteau
 Dan Parisien
 William Park
+Claude Paroz
 Heikki Partanen
 Harri Pasanen
 Gaël Pasgrimaud

Misc/NEWS

@@ -10,6 +10,9 @@ Release date: TBA
 Core and Builtins
 -----------------
 
+- Issue #16324: _charset parameter of MIMEText now also accepts
+  email.charset.Charset instances. Initial patch by Claude Paroz.
+
 - Issue #1764286: Fix inspect.getsource() to support decorated functions.
   Patch by Claudiu Popa.