bpo-41260: C impl of datetime.date.strftime() takes different keyword…

… arg (GH-21712)

Lib/datetime.py

@@ -1032,13 +1032,13 @@ def ctime(self):
             _MONTHNAMES[self._month],
             self._day, self._year)
 
-    def strftime(self, fmt):
+    def strftime(self, format):
         """
         Format using strftime().
 
         Example: "%d/%m/%Y, %H:%M:%S"
         """
-        return _wrap_strftime(self, fmt, self.timetuple())
+        return _wrap_strftime(self, format, self.timetuple())
 
     def __format__(self, fmt):
         if not isinstance(fmt, str):

Lib/test/datetimetester.py

@@ -1489,6 +1489,9 @@ def test_strftime(self):
         #check that this standard extension works
         t.strftime("%f")
 
+        # bpo-41260: The parameter was named "fmt" in the pure python impl.
+        t.strftime(format="%f")
+
     def test_strftime_trailing_percent(self):
         # bpo-35066: Make sure trailing '%' doesn't cause datetime's strftime to
         # complain. Different libcs have different handling of trailing

Misc/NEWS.d/next/Library/2020-08-02-23-46-22.bpo-41260.Q2BNzY.rst

@@ -0,0 +1,2 @@
+Rename the *fmt* parameter of the pure Python implementation of
+:meth:`datetime.date.strftime` to *format*.