New submission from Kevin <kfbrit...@gmail.com>:
>>> # Measure some strings: ... words = ['cat', 'window', 'defenestrate'] >>> for w in words: ... print(w, len(w)) ... cat 3 window 6 defenestrate 12 If you need to modify the sequence you are iterating over while inside the loop (for example to duplicate selected items), it is recommended that you first make a copy. Iterating over a sequence does not implicitly make a copy. The slice notation makes this especially convenient: >>>>>> for w in words[:]: # Loop over a slice copy of the entire list. ... if len(w) > 6: ... words.insert(0, w) ... >>> words ['defenestrate', 'cat', 'window', 'defenestrate'] words is a tuple and is immutable ---------- assignee: docs@python components: Documentation messages: 351331 nosy: Derangedn00b, docs@python priority: normal severity: normal status: open title: Tutorial: 4.2. for Statements type: compile error versions: Python 3.7 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue38058> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
