map Function in Python

map function in Python is a convenient way to execute function for a collection. Let’s see an example that does not use map function.

class playground(unittest.TestCase):
    def pow(self, n):
        return n**n

    def test_pow(self):
        numbers = range(10)
        for number in numbers:
            result = self.pow(number)
            print(result)

Output:

1
1
4
27
256
3125
46656
823543
16777216
387420489

The example above just executes the pow function sequentially for every item in the integer list.

If you use a map function, the code becomes concise and easier to manage. It might be a little confusing but if you get used to it, it’s not too bad.

class playground(unittest.TestCase):
    def pow(self, n):
        return n**n

    def test_map(self):
        numbers = range(10)
        results = map(self.pow, numbers)
        print(list(results))

Output:

[1, 1, 4, 27, 256, 3125, 46656, 823543, 16777216, 387420489]

I didn’t know 0^0 was 1… I knew n^0 was always 1 but… Interesting. 🙂

Author: admin

A software engineer in greater Seattle area

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