recursive map on nested list
Hello, I'd like to apply a function to elements of a nested list and wondered if there is anything more idiomatic and/or shorter than this recursive way: >>> def recur_map(f, data): ... if isinstance(data, list): ... mapped_list = [] ... for i in data: ... mapped_list.append(recur_map(f, i)) ... return mapped_list ... else: ... return f(data) ... >>> recur_map(lambda x: x*2, [[1, 2], 3, 4, [5, 6, [7, 8]]]) [[2, 4], 6, 8, [10, 12, [14, 16]]] Thanks, alex -- http://mail.python.org/mailman/listinfo/python-list
Re: recursive map on nested list
I think for most purposes a program like this is short enough: def recur_map2(fun, data): if hasattr(data, "__iter__"): return [recur_map2(fun, elem) for elem in data] else: return fun(data) data = [set([1, 2]), [3], 4, [5, {6:4}, [7, 8]]] print recur_map2(lambda x: x*2, data) Bye, bearophile -- http://mail.python.org/mailman/listinfo/python-list
Re: recursive map on nested list
Uglier than yours, but down to two lines: def recur_map(f, data): return [ not hasattr(x, "__iter__") and f(x) or recur_map(f, x) for x in data ] -- http://mail.python.org/mailman/listinfo/python-list