Turn string into operator

How about using a lookup dict, but with lambdas instead of operator library.

op = {'+': lambda x, y: x + y,
      '-': lambda x, y: x - y}

Then you can do:

print(op['+'](1,2))

And it will output:

3

Use eval() if it is safe (not on servers, etc):

num_1 = 5

num_2 = 10

op = ['+', '-', '*']

result = eval(f'{num_1} {op[0]} {num_2}')

print(result)

Output : 15

I understand that you want to do something like: 5"+"7 where all 3 things would be passed by variables, so example:

import operator

#define operators you wanna use
allowed_operators={
    "+": operator.add,
    "-": operator.sub,
    "*": operator.mul,
    "/": operator.truediv}

#sample variables
a=5
b=7
string_operator="+"

#sample calculation => a+b
result=allowed_operators[string_operator](a,b)
print(result)

I was bugged with the same problem, using Jupyter Notebook, I was unable to import the operator module. So the above code helped give me insight but was unable to run on the platform. I figured out a somehwhat primitive way to do so with all the basic funcs and here it is: (This could be heavily refined but it’s a start…)

# Define Calculator and fill with input variables
# This example "will not" run if aplha character is use for num1/num2 
def calculate_me():
    num1 = input("1st number: ")
    oper = input("* OR / OR + OR - : ")
    num2 = input("2nd number: ")

    add2 = int(num1) + int(num2)
    mult2 = int(num1) * int(num2)
    divd2 = int(num1) / int(num2)
    sub2 = int(num1) - int(num2)

# Comparare operator strings 
# If input is correct, evaluate operand variables based on operator
    if num1.isdigit() and num2.isdigit():
        if oper is not "*" or "/" or "+" or "-":
            print("No strings or ints for the operator")
        else:
            pass
        if oper is "*":
            print(mult2)
        elif oper is "/":
            print(divd2)
        elif oper is "+":
            print(add2)
        elif oper is "-":
            print(sub2)
        else:
            return print("Try again")

# Call the function
calculate_me()
print()
calculate_me()
print()