Python
while True:
    print("choose 1,2,3")
    choise = int(input("Enter num "))
    if choise == 1:
        print("1")
    elif choise == 2:
        print("2")
choose 1,2,3
1
choose 1,2,3
2
choose 1,2,3

line 3, in <module>
    choise = int(input("Enter num "))
             ^^^^^^^^^^^^^^^^^^^^^^^^
ValueError: invalid literal for int() with base 10: ''