CS50 Help

import sys
from tabulate import tabulate
import csv

def Tabulater(data):
    try:
        with open(data) as inp:
            reader = csv.reader(inp)
            print(tabulate(reader, headers = "firstrow", tablefmt = "grid"))
    except FileNotFoundError:
        sys.exit("File does not exist")

def main():
    if(len(sys.argv) < 2):
        sys.exit("Too few command-line arguments")
    elif(len(sys.argv) > 2):
        sys.exit("Too many command-line arguments")
    elif(sys.argv[1][-4:] != ".csv"):
        sys.exit("Not a CSV file")
    else:
        print(Tabulater(sys.argv[1]))


if __name__ == "__main__":
    main()