CODEWITHSUNDEEP
pythonfunctionvariables
Ashish Kumar
Ashish Kumar

Reputation: 1

I am a new learner in python and I can't understand how these codes containing functions work

def createmultipier(x):
    return lambda y: y*x
multiply= createmultipier(10)
print(multiply(15))

Here multiply is a variable then how did he put value to it and how did that work?

Upvotes: 0

Views: 53

Answers (1)

Samwise
Samwise

Reputation: 71542

createmultiplier(10) creates a function that multiplies its argument by 10. That's what multiply is assigned to -- hence multiply(15) returns 150.

To put it another way:

multiply = createmultiplier(10)

has the same effect as doing:

def multiply(y)
    return 10 * y

The point of a function like createmultiplier is to let you create functions without a def statement and without having to hard-code implementation details like the constant 10. For example, if you wanted multipliers for all numbers from 1 to 4, you could do:

def times_1(y):
    return 1 * y

def times_2(y):
    return 2 * y

def times_3(y):
    return 3 * y

def times_4(y):
    return 4 * y

multipliers = [times_1, times_2, times_3, times_4]
print([m(10) for m in multipliers])  # [10, 20, 30, 40]

but it's much easier to do:

def create_multiplier(x):
    return lambda y: y*x

multipliers = [create_multiplier(x) for x in range(1, 5)]
print([m(10) for m in multipliers])  # [10, 20, 30, 40]

Upvotes: 2

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