Calling a function using exec

Question

Trying to call a function as a string using exec but it doesn't work. I attached a simple example code below.

I get an error that square_it() is missing 1 required positional argument: 'num.' I know it is missing but I don't know how to have the argument in that globals syntax.

Below is an example:

def square_it(num):
 result = num * num
 return result
def test():
 #code_globals = {}
 globals()['square_it']()
 code_locals = {'testing':0}
 comd_str = "testing = square_it(2)"
 exec(comd_str, globals(), code_locals)
 print(code_locals['testing'])
test()

• martineau: If you read the traceback for the error closely, you'll see that it is ocurring on line the globals()['square_it']() because that is where the function is being called with no arguments — not via the exec() (execution never gets that far).

Answer 1

The error isn't happening in the exec call; it's happening in the first line, when you call globals. All the rest of the code is irrelevant.

Calling the function there is exactly the same as doing it any other way; you have the calling parentheses, you just need to put your argument in there:

globals()['square_it'](2)