New submission from Yechoh <martin.huy...@home.nl>:
Suppose we have: forest = [[1,2],[3,4]] and we want: l1 = [['1','2'],['3','4']] we could write: l1 = [[str(leaf) for leaf in tree] for tree in forest] Now if we want: l2 = ['1','2','3','4'] What I expect to need to write is: l2 = [str(leaf) for leaf in tree for tree in forest] However, this gives an error: Traceback (most recent call last): File "<input>", line 1, in <module> NameError: name 'tree' is not defined Instead, I should write: l2 = [str(leaf) for tree in forest for leaf in tree] Notice the different order. I would prefer if the first version of constructing l2 over the second, since it follows closer to the reading order. Also, it is closer to the comprehension for a nested list, so changing a nested list comprehension to a flattened list comprehension is easy. ---------- messages: 329906 nosy: Yechoh priority: normal severity: normal status: open title: list comprehension for flattened or nested list differ too much type: enhancement _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue35245> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
