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I understand that with one list argument map() can be replaced by a list comprehension. For example
map(lambda x : x**2, range(5))
can be replaced with
[x**2 for x in range(5)]
Now how would I do something similar for two parallel lists. In other words, I have a line of code with the following pattern:
map(func, xs, ys)
where func() takes two arguments.
How can I do the same thing with a list comprehension?
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6. What is the list comprehension equivalent for: list(map(lambda x:x**-1, [1, 2, 3]))? Explanation: The output of the function list(map(lambda x:x**-1, [1, 2, 3])) is [1.0, 0.5, 0.3333333333333333] and that of the list comprehension [x**-1 for x in [1, 2, 3]] is [1.0, 0.5, 0.3333333333333333].
Map function is faster than list comprehension when the formula is already defined as a function earlier. So, that map function is used without lambda expression.
The question was: 'is it possible to return two lists from a list comprehension? '. I answer that it is possible, but in my opinion is better to iterate with a loop and collect the results in two separate lists.
map() with multiple arguments is the equivalent of using the zip() function on those extra arguments. Use zip() in a list comprehension to do the same:
[func(x, y) for x, y in zip(xs, ys)]
Generally speaking, any map(func, a1, a2, .., an) expression can be transformed to a list comprehension with [func(*args) for args in zip(a1, a2, .., an)].
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