solution to: https://www.youtube.com/watch?v=W2Nz3733mCw&lc=z222zbry0m3ogrpj404t1aokg0k1ngnhw55naycpr2chbk0h00410.1565984354643611

Nesting Functions and Decorators.py

#!/usr/bin/env python
""" author: svmihar
problem source: https://www.youtube.com/watch?v=W2Nz3733mCw&lc=z222zbry0m3ogrpj404t1aokg0k1ngnhw55naycpr2chbk0h00410.1565984354643611
"""

# problem1
# adder(5)(3) --> 8
def adder(x):
    def wrapper(y):
        return x+y
    return wrapper


print('problem 1')
print(adder(5)(3))

# problem2
# partial(add,1)(3) --> 4
def add(n,m):
    return (n+m)
def partial(fn,x):
    def wrapper(y):
        return fn(x,y)
    return wrapper


print('problem 2')
print(partial(add, 1)(3))

# problem 3
# summator = make_summator()
# summator(1) --> 1
# summator(3) --> 4
# summator(4) --> 8
def summator():
    x = 0
    def sabi(n):
        nonlocal x
        x += n
        return x
    return sabi


sedap = summator()
print('problem 3')
sedap(1)
sedap(3)
print(sedap(4))

# problem 4
# @cache
# add(5,3) --> 8
# add(1,2) --> 8
# add(4,6) --> 8

def cache1(function):
# solution 1: with if
    asu = []

    def wrapper(*args):
        if function(*args) in asu: 
            return asu[0]
        else: 
            asu.append(function(*args))
            return asu[0]
    return wrapper

def cache2(fn): 
# solution 2: assigning the function on nonlocal variable
    asu = []
    def wrapper(*args):
        asu.append(fn(*args))
        return asu[0]
    return wrapper

@cache1
def add(a, b):
    return a+b

@cache2 
def add_(a,b): 
    return a+b

print('problem 4')
add(1, 3)
add(2, 4)
print(add(3, 5))
print(add(3, 9))
print(10*'=')
add_(1, 3)
add_(2, 4)
print(add_(3, 5))
print(add_(3, 9))