On Tue, Aug 16, 2016 at 5:18 PM, Ian Kelly <ian.g.ke...@gmail.com> wrote: > Also, unless the mapped function is already defined (and preferably > built-in), a generator expression or list comprehension is usually more > readable and avoids the significant overhead of repeatedly calling a Python > function.
Don't know why "built-in" is significant, but most of the point of map() is to make use of an existing function: # Instead of lengths = (len(x) for x in items) # Use lengths = map(len, items) One problem: Not all languages have map() defined the same way. Built-in function or method? If function, what order are the arguments in? If method, is it a method on a function or an array/list? If you add extra arguments, are they treated as parallel arrays, or are they static arguments to the function - or are they not allowed at all? Actually, I've never seen map as a function method (which would be used as "len.map(items)"). All the others, I've seen in various different languages. Can anyone fill in the gap? ChrisA -- https://mail.python.org/mailman/listinfo/python-list
