x.py

x.py

import cmd

from pprint import pprint

class Calculator(cmd.Cmd):
    def get_floats(self, line, number = None):
        ''' get number of floats from line
            if number is None, don't worry about the number returned
            if cannot float anything in the line it prints help and raises
            ValueError
        '''
        try:
            floats = tuple(map(float, line.split()))
            if number is not None and len(floats) != number:
                raise ValueError('Need more floats!')

            return floats
        except ValueError as e:
            print('Error: {}'.format(e))
            print('The correct syntax is')
            self.print_help()
            raise e

    def print_help(self):
        ''' print the help from the last command run '''
        cmd, arg, line = self.parseline(self.lastcmd)
        self.onecmd('help {}'.format(cmd))

    def do_mpg(self, line):
        ''' calculate MPG from [miles], [fuel] '''
        try:
            miles, fuel = self.get_floats(line, 2)
        except ValueError:
            return

        print('\tMPG = {}'.format(miles/fuel))

    def do_pay(self, line):
        try:
            hours, wage = self.get_floats(line, 2)
        except ValueError:
            return
        money = min(hours,40) * wage
        money += max(0, hours - 40) * wage * 1.5
        print('total pay {} * {} = {}'.format(
            hours, wage, money))


    def do_EOF(self, line):
        ''' quit on an empty line '''
        return True

if __name__ == '__main__':
    Calculator().cmdloop()