Define a function mysum(seq) that returns the sum of all numbers in the list seq.

def mysum(seq):
    """Return the sum of all numbers in seq.
    In:
        seq - a sequnce of summable items
    Out:
        sum of all items in seq
    """

Library

x = [1,2,3,4]
sum = sum(x)
print(sum) # Output: 10