Converting characters in Python to int?

Question

Python

Could you please tell me why Python can't translate math characters (*, +, - ...) from str to int? The essence of the problem is that I have a string "150 x 81" (with spaces) and I need to calculate this example. If you just replace "x" with "*", then after python does not allow you to convert "*" to int type.

Answer 1

I don't know why you need this, but it works great:

>>> literal_expr = '150 x 81'
>>> eval(literal_expr.replace('x', '*'))
12150

Answer 2

Op:

x = '150 x 81'
x1 = x.split('x')
y = int(x1[0]) * int(x1[1]) #12150

Answer 3

The operators +, *, -, / have no type - they do not refer to int, float, or bool, so they cannot be converted to any type.
But you can count them and set the operation algorithm. Here is one option for multiplication. By analogy, it can be used with other operations (/, +, -, **, //, etc.)

string = "150 x 5"
for index in range(len(string.split())):
    if string.split()[index] == "x":
        answer = int(string.split()[index-1]) * int(string.split()[index+1])
print (answer)

But it is suitable for a simple equation with two numbers. If the equations are more complex, then it is better to use the eval(string) function. This function will also save the algebraic rules (first do multiplication and division, operations in brackets, and then addition and subtraction, etc.)