order_by_even.py

def foo(arr):
    i = 0 
    j = len(arr) - 1
    while i <= j:
        if (arr[i] % 2) != 0:
            n = arr.pop(i)
            arr.insert(len(arr), n)
        else:
            n = arr.pop(i)
            arr.insert(0, n)
        i+=1
        if (arr[j] % 2) != 0:
            n = arr.pop(j)
            arr.insert(len(arr), n)
        else:
            n = arr.pop(j)
            arr.insert(0, n)
        j-=1
        
    print(arr)
    return arr