I wonder if it is possible to simplify and clean up this code by using iteratools?)

"while len(array)> 0" is equivalent to "while array"

You have a nice solution.
Could you help me figure out?
Can you tell why the same but with the exec does not work?
On startup it gives an error that the variable "rezult" is undefined, although the exec initializes this variable.
But if run finction in terminal on PC, it works

def calc (txt):
mod = txt.split()
exec(f"rezult = { len(mod[0])}{mod[1]}{len(mod[2])}")

return '.'*rezult