bpo-41774: Add programming FAQ entry (GH-22402)

miss-islington · terryjreedy · web-flow · commit 868c8e41eb1d · 2020-09-28T22:27:06.000-07:00
In the "Sequences (Tuples/Lists)" section, add "How do you remove multiple items from a list". (cherry picked from commit 5b0181d) Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
diff --git a/Doc/faq/programming.rst b/Doc/faq/programming.rst
@@ -1164,6 +1164,21 @@ This converts the list into a set, thereby removing duplicates, and then back
 into a list.
 
 
+How do you remove multiple items from a list
+--------------------------------------------
+
+As with removing duplicates, explicitly iterating in reverse with a
+delete condition is one possibility.  However, it is easier and faster
+to use slice replacement with an implicit or explicit forward iteration.
+Here are three variations.::
+
+   mylist[:] = filter(keep_function, mylist)
+   mylist[:] = (x for x in mylist if keep_condition)
+   mylist[:] = [x for x in mylist if keep_condition]
+
+If space is not an issue, the list comprehension may be fastest.
+
+
 How do you make an array in Python?
 -----------------------------------
 
diff --git a/Misc/NEWS.d/next/Documentation/2020-09-24-15-35-13.bpo-41774.5IqdGP.rst b/Misc/NEWS.d/next/Documentation/2020-09-24-15-35-13.bpo-41774.5IqdGP.rst
@@ -0,0 +1,2 @@
+In Programming FAQ "Sequences (Tuples/Lists)" section, add "How do you
+remove multiple items from a list".

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+In Programming FAQ "Sequences (Tuples/Lists)" section, add "How do you`
	`2`	`+remove multiple items from a list".`