Push Zeros to end.py

# ou have been given a random integer array/list(ARR) of size N. 
# You have been required to push all the zeros that are present in the array/list to the end of it. 
# Also, make sure to maintain the relative order of the non-zero elements.

from sys import stdin


def pushZerosAtEnd(arr, n):
    #Your code goes here
    nonZero = 0
    for i in range(n):
        if arr[i] != 0:
            temp = arr[i]
            arr[i] = arr[nonZero]
            arr[nonZero] = temp
            nonZero += 1


#Taking Input Using Fast I/O
def takeInput():
    n = int(stdin.readline().rstrip())

    if n == 0:
        return list(), 0

    arr = list(map(int, stdin.readline().rstrip().split()))
    return arr, n


#to print the array/list
def printList(arr, n):
    for i in range(n):
        print(arr[i], end=" ")

    print()


#main
t = int(stdin.readline().strip())

while t > 0:

    arr, n = takeInput()

    pushZerosAtEnd(arr, n)
    printList(arr, n)

    t -= 1