Closes #19475: Added timespec to the datetime.isoformat() method.

Added an optional argument timespec to the datetime isoformat() method
to choose the precision of the time component.

Original patch by Alessandro Cucci.
diff --git a/Misc/ACKS b/Misc/ACKS
index 5e6fee7..adc6848 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -309,6 +309,7 @@
 Simon Cross
 Felipe Cruz
 Drew Csillag
+Alessandro Cucci
 Joaquin Cuenca Abela
 John Cugini
 Tom Culliton
diff --git a/Misc/NEWS b/Misc/NEWS
index 9c94db3..d90422d 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -201,6 +201,9 @@
 Library
 -------
 
+- Issue #19475: Added an optional argument timespec to the datetime
+  isoformat() method to choose the precision of the time component.
+
 - Issue #2202: Fix UnboundLocalError in
   AbstractDigestAuthHandler.get_algorithm_impls.  Initial patch by Mathieu Dupuy.