https://github.com/python/cpython/commit/868c8e41eb1d7dc032679ae06e62c0d60ed... commit: 868c8e41eb1d7dc032679ae06e62c0d60edd7725 branch: 3.9 author: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> committer: GitHub <noreply@github.com> date: 2020-09-28T22:27:06-07:00 summary: bpo-41774: Add programming FAQ entry (GH-22402) In the "Sequences (Tuples/Lists)" section, add "How do you remove multiple items from a list". (cherry picked from commit 5b0181d1f6474c2cb9b80bdaf3bc56a78bf5fbe7) Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu> files: A Misc/NEWS.d/next/Documentation/2020-09-24-15-35-13.bpo-41774.5IqdGP.rst M Doc/faq/programming.rst diff --git a/Doc/faq/programming.rst b/Doc/faq/programming.rst index 66d210a55fac7..1435765063f73 100644 --- 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 new file mode 100644 index 0000000000000..af8e02437cb2b --- /dev/null +++ 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".