app.py

#!/usr/bin/python3.9
# Tests pass on Mac OS 11.3 Running Python 3.9.4
"""
Copyright 2021 Ashley Hines

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

     https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

Formatted in accordance with PEP-8 Using Black
"""

## Imports
import sys
import GUI
import CLI
import constants as CONSTS

## Start of program ARGS Parser (Effectively Main() - Allows import without calling function.)
if __name__ == "__main__":
    # Get System Args to check if GUI or CLI
    if len(sys.argv) > 1:
        ## Checks if application has Arguments
        # print(sys.argv[1])
        # print(sys.argv[1].lower())
        if sys.argv[1].lower() == "cli":
            ## Call CLI
            cli = CLI.CLI()
            cli.cliMenu()
        else:
            ## Print out version + Syntax for app entry
            print("Pay Calculator {}".format(CONSTS.C_VERSION))
            print(
                "Invalid Argument - Syntax should be 'python3 app.py cli' or 'python3 app.py'"
            )
            ## Kill application
            sys.exit(1)
    else:
        ## call GUI
        GUI.start()