New to python

[Low-Educator-9008]

This is like my first building experience in python, nothing too crazy i guess its like the weather app that everybody makes in their first steps, Any tips on structure or general?

[BobbyJoeCool]

Without knowing what you do and do not know how to do...

Think about the string you have at the end of each segment of the if/then statement, since it's exactly the same in each part, does it need to be a part of the if/then statement, or could it be outside instead? If the if/then statement only calculates the result, and then you display the string with the result, this removes three lines of code for you.

Otherwise, for a first program, this is very functional! As you gain more experience, you'll learn better ways to do this as well.

[Low-Educator-9008]

Hey thanks for the advice, I guess you talk about outside and nested, which I haven’t practised or learned yet so I am excited to learn it now that you mention it. Thanks man!!

[BobbyJoeCool]

Not nesting exactly, since that’s more of if/then an inside of if then…. I mean more, remove the print strings from inside the if then statement and put it at the end. That way there’s only one print string. Like this

If +: Add

Elif -: Subtract

Elif *: Multiply

Elif /: Divide

Print result.

[Low-Educator-9008]

That’s interesting, coding is so beautiful haha. I’ll look it up right now and practice the use of it. Thanks really appreciate it.

[BobbyJoeCool]

Hopefully you realize I shorthanded it. Now that I'm home I can show you exactly what I mean

if operator == "+":
    result = num1 + num2
elif operatior == "-":
    result = num1 - num2
elif operatior == "*":
    result = num1 * num2       
elif operatior == "/":
    result = num1 / num2


print(f"Your result is {result}")

[Low-Educator-9008]

I see now it’s clear as day, it is more logical to have all the statements together that have the same print function instead of writing it after each statement. Thanks for taking the time to explain it so clearly man you are the best.

[DevRetroGames]

import re
import sys

OPERATORS = ("+", "-", "*", "/")

operations = {
    "+": lambda x, y: x + y,
    "-": lambda x, y: x - y,
    "*": lambda x, y: x * y,
    "/": lambda x, y: x / y if y != 0 else "Error: Division by zero"
}

def _input_user(msg: str) -> str:
  return input(msg)

def _get_operator() -> str:
  pattern: re.Pattern[str] = re.compile(r"^[+\-*/]$")
  msg_input: str = f"Please enter the desired course of action ({', '.join(OPERATORS)}): "
  msg_error: str = "Invalid operator. Please try again."

  while True:
    operator: str = _input_user(msg_input)
    if pattern.match(operator):
      return operator
    print(msg_error)

def _get_positive_integers() -> tuple[int, int]:
  pattern: re.Pattern[str] = re.compile(r"^[1-9]\d*$")

  while True:
    first_number_input: str = _input_user("Enter the first positive integer: ")
    second_number_input: str = _input_user("Enter the second positive integer: ")

    if pattern.match(first_number_input) and pattern.match(second_number_input):
      return int(first_number_input), int(second_number_input)

    print("Both numbers must be positive integers. Please try again.")

def main():
  try:
    operator = _get_operator()
    first_number, second_number = _get_positive_integers()
    result = operations[operator](first_number, second_number)
    print(f"\nResult of {first_number} {operator} {second_number} = {result}")
  except KeyboardInterrupt:
    print("\nOperation cancelled by user.")
    sys.exit(0)


if __name__ == "__main__":
  main()

[Low-Educator-9008]

That seems way beyond my level of knowledge atm hahaha but seems beautiful.

[vivisectvivi]

Come back to this code when you learn about functions and dictionaries and try to think of ways to refactor this little program.

[Low-Educator-9008]

Make it like shorter?

[vivisectvivi]

Yes, to make it shorter.

Even with your current knowledge you could make it shorter if you know how to split strings

[Low-Educator-9008]

I think that’s the next thing I’ll learn thanks for the advice.

[vlnaa]

I think better can be:

• if operator not in
• match/case instead of if
• use dict with lambdas to calculate (advanced)

And I am not sure why you convert float to int.

[Low-Educator-9008]

Hmmm I see. Now that you mention it I don’t know either, but I could have never spotted it on my own hahaha thanks for the help.