Enter the first number: 2
Enter the second number: 10
Enter an operator (valid operators are +, -, *, / and pow): pow
1024.0

#A basic calculator which supports +, -, *, / and pow

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

def sub(a, b):
    return a - b

def mul(a, b):
    return a * b

def div(a, b):
    return a / b

def pow(a, b):
    return a ** b

if __name__ == "__main__":
    while True:
        try:
            number1 = float(input("Enter the first number: "))
            number2 = float(input("Enter the second number: "))
        except:
            print("That is not a number!")
            continue

        operator = input("Enter an operator (valid operators are +, -, *, / and pow): ")

        #Check if user operator is a valid one
        if operator == "+":
            func = add
        elif operator == "-":
            func = sub
        elif operator == "*":
            func = mul
        elif operator == "/":
            func = div
        elif operator == "pow":
            func = pow
        else:
            print("Invalid operator!")
            continue

        #Print result
        print(func(number1, number2))

operators = {
    "+": add,
    "-": sub,
    "*": mul,
    "/": div,
    "pow": pow
}

func = operators.get(operator, None)
if func is None:
    print("Invalid operator!")
    continue

def main():
    while True:
        number1, number2, operator = get_user_input()
        func = operators.get(operator, None)
        if func is None:
            print("Invalid operator!")
            continue

        print(func(number1, number2))

if __name__ == '__main__':
    main()

import operator

operators = {
    "+": operator.add,
    "-": operator.sub,
    "*": operator.mul,
    "/": operator.truediv,
    "pow": operator.pow
}

except ValueError:

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


    def sub(a, b):
        return a - b


    def mul(a, b):
        return a * b


    def div(a, b):
        return a / b


    def mypow(a, b):
        return a ** b


    if __name__ == "__main__":
        operator_map = {"+": add, "-": sub, "*": mul, "/": div, "pow": mypow}

        while True:
            try:
                number1 = float(input("Enter the first number: "))
                number2 = float(input("Enter the second number: "))
            except ValueError:
                print("That is not a number!")
                continue

            operator = input("Enter an operator (valid operators are +, -, *, / and pow): ")
            print(operator_map[operator](number1, number2) if operator in operator_map else "Invalid operator!")

def binary_operation(operation, left, right):
    """Returns the result of applying operation to its arguments."""
    return operator_map[operation](left, right)

binary_operation('+', 2, 3)
binary_operation(sys.argv[1], float(sys.argv[2]), float(sys.argv[3]))

binary_operation(input('operator'), float(input('number')), float(input('number'))

binary_operation('*', 5.0 binary_operation('+' 2, 3))

def get_answer(num1, num2, op):
    ...
if __name__ == '__main__':
    while True:
        try:
            number1 = float(input(...))
            number2 = float(input(...))
        except ValueError:
            print("That is not a number!")
            continue
        operator = input(...)
        answer = get_answer(number1, number2, operator)
        if answer is None:
            print("Invalid operator!")
        else:
            print(answer)

import operator

operators = {
    '+': operator.add,
    '-': operator.sub,
    '*': operator.mul,
    '/': operator.truediv,
    '%': operator.mod,
    '^': operator.pow,
    '//': operator.floordiv,
    '>': operator.gt,
    '<': operator.lt,
    '=': operator.eq,
    '!=': operator.ne,
    '>=': operator.ge,
    '<=': operator.le,
}

def get_answer(num1, num2, op):
    try:
        return operators[op](num1, num2)
    except IndexError:
        raise ValueError("Invalid operator")

if __name__ == '__main__':
    operator_string = ', '.join(operators)
    print("Valid operators: {}n".format(operator_string))
    while True:
        try:
            number1 = float(input("Enter the first number: "))
            number2 = float(input("Enter the second number: "))
        except ValueError:
            print("That is not a number!")
            continue
        except (KeyboardInterrupt, EOFError):
            break # exit
        op = input("Enter an operator: ")
        try:
            print(get_answer(number1, number2, op))
        except ValueError:
            print("Invalid operator!")