congruence.py

#!/usr/bin/python3
import re

def congruence(a, b, n, **kwargs):
    if kwargs["verbose"] != None:
        if kwargs["verbose"] == True:
            verbose = True
        else:
            verbose = False

    if verbose == True:
        print("a = {}\nb = {}\nn = {}".format(a, b, n))
        print("({} - {}) (mod {}) = {}\n".format(a, b, n, (a-b) % n))

    if (a-b) % n == 0:
        print("{} ≡ {} (mod {}) = 0".format(a, b, n))
        print("{} and {} are congruent (mod {})".format(a, b, n))
    else:
        print("{} ≡ {} (mod {}) = {}".format(a, b, n, (a-b) % n))
        print("{} and {} are not congruent (mod {})".format(a, b, n))

def main():
    try:
        while True:
            u_input = input("> ")
            u_input = re.sub("\s", "", u_input)

            #print(u_input)

            if re.findall("--help", u_input) or re.findall("-h", u_input):
                print("Usage: [flags] a, b, n")
                print("\t-h --help: Display this help.")
                print("\t-v --verbose: Display more data.")
                print("\t-q --quit: Quit the program.")
                continue
            elif re.findall("--quit", u_input) or re.findall("-q", u_input):
                break

            variables = re.findall("(\d*?),", u_input)
            variables.append(re.findall(".*,(\d*?)$", u_input)[0])

            #for item in variables:
            #    print(variables)

            a = int(variables[0])
            b = int(variables[1])
            n = int(variables[2])
            
            if (re.findall("--verbose", u_input) or
                re.findall("-v", u_input)):
                congruence(a, b, n, verbose=True)
            else:
                congruence(a, b, n, verbose=False)

    except Exception as e:
        print("Unexpected exception:\n\t\"{}\"".format(e))
        main()

main()