https://github.com/python/cpython/commit/d0c32ae419316cb0d6f06ec8cb2f6b91a878070f commit: d0c32ae419316cb0d6f06ec8cb2f6b91a878070f branch: 3.12 author: Miss Islington (bot) <[email protected]> committer: terryjreedy <[email protected]> date: 2024-03-13T05:36:43Z summary:
[3.12] gh-111307: Update design FAQ 'switch' entry (GH-115899) (#116703) (cherry picked from commit 43986f55671ba2f7b08f8c5cea69aa136a093697) Co-authored-by: Terry Jan Reedy <[email protected]> files: M Doc/faq/design.rst diff --git a/Doc/faq/design.rst b/Doc/faq/design.rst index 300e1b6cc40a58..c8beb64e39bc1a 100644 --- a/Doc/faq/design.rst +++ b/Doc/faq/design.rst @@ -259,9 +259,11 @@ is evaluated in all cases. Why isn't there a switch or case statement in Python? ----------------------------------------------------- -You can do this easily enough with a sequence of ``if... elif... elif... else``. -For literal values, or constants within a namespace, you can also use a -``match ... case`` statement. +In general, structured switch statements execute one block of code +when an expression has a particular value or set of values. +Since Python 3.10 one can easily match literal values, or constants +within a namespace, with a ``match ... case`` statement. +An older alternative is a sequence of ``if... elif... elif... else``. For cases where you need to choose from a very large number of possibilities, you can create a dictionary mapping case values to functions to call. For @@ -290,6 +292,9 @@ It's suggested that you use a prefix for the method names, such as ``visit_`` in this example. Without such a prefix, if values are coming from an untrusted source, an attacker would be able to call any method on your object. +Imitating switch with fallthrough, as with C's switch-case-default, +is possible, much harder, and less needed. + Can't you emulate threads in the interpreter instead of relying on an OS-specific thread implementation? -------------------------------------------------------------------------------------------------------- _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/python-checkins.python.org/ Member address: [email protected]
