PyDOS Version 3.0

Question

This is a follow up to the questions: PyDOS shell simulation and PyDOS: Version 2.0

Introducing PyDOS 3.0! With brand new features and improved code, this will blow your mind!

New Features (This list will be updated with PyWrite soon)

• Dialogs are now in a window like design.

• New start-screen, easier to use.

• Create your own name and change it!

• New Commands Dictionary

• PyCALC is now called SimpleCalc

If you have any ideas for improvements, don't hesitate to post them!

Source Code:

#PyDOS Version 3.0 - Written by Mrfunny744
import time
import os
import sys
import random
def ChangeName():
 os.system('cls' if os.name == 'nt' else 'clear')
 print ("----------------------------------------------")
 name = input ("Type in your new username: ")
 print()
 print ("This can be changed again if you wish.")
 print ("----------------------------------------------")
 time.sleep(2.5)
def shutdown():
 print ("------------------------")
 print ("| |")
 print ("| Thank you for using |")
 print ("| PyDOS |")
 print ("| |")
 print ("| |")
 print ("| |")
 print ("| Shutting Down... |")
 print ("| |")
 print ("------------------------")
 sys.exit(0)
def end():
 print ("------------------------------------")
 print ("| |")
 print ("| Thanks for using SimpleCalc! |")
 print ("| |")
 print ("------------------------------------")
 time.sleep(2)
def calc_a():
 print ("----------------------------------")
 num1 = int(input("Enter a number: "))
 num2 = int(input("Enter a number: "))
 print ("----------------------------------")
 answer = num1+num2
 print ("Your answer is:" ,answer)
 print ("----------------------------------")
 time.sleep(3)
 end()
def calc_m():
 print ("----------------------------------")
 num1 = int(input("Enter a number: "))
 num2 = int(input("Enter a number: "))
 print ("----------------------------------")
 answer = num1*num2
 print ("Your answer is:" ,answer)
 print ("----------------------------------")
 time.sleep(3)
 end()
def calc_s():
 print ("----------------------------------")
 num1 = int(input("Enter a number: "))
 num2 = int(input("Enter a number: "))
 print ("----------------------------------")
 answer = num1-num2
 print ("Your answer is:" ,answer)
 print ("----------------------------------")
 time.sleep(3)
 end()
def calc_d():
 print ("----------------------------------")
 num1 = int(input("Enter a number: "))
 num2 = int(input("Enter a number: "))
 print ("----------------------------------")
 answer = num1/num2
 print ("Your answer is:" ,answer)
 print ("----------------------------------")
 time.sleep(3)
 end()
def simplecalc():
 print ("--------------------------")
 print ("| |")
 print ("| Welcome to SimpleCalc |")
 print ("| |")
 print ("| A = Add |")
 print ("| M = Multiply |")
 print ("| S = Subtract |")
 print ("| D = Divide |")
 print ("| Q = Quit |")
 print ("| |")
 print ("--------------------------")
 print ("| |")
 choice = input ("| Choice: |")
 print ("| |")
 print ("--------------------------")
 if choice == 'a':
 calc_a()
 elif choice == 'm':
 calc_m()
 elif choice == 's':
 calc_s()
 elif choice == 'd':
 calc_d()
 elif choice == 'q':
 end()
 else:
 print ("Invalid specifacation.")
def error_message():
 os.system('cls' if os.name == 'nt' else 'clear')
 print ("----------------------")
 print ("| Whoops! |")
 print ("| |")
 print ("| |")
 print ("| It dosent look |")
 print ("| like the app |")
 print ("| exists. |")
 print ("| |")
 print ("|Check and try again.|")
 print ("----------------------")
 time.sleep(3)
os.system('cls' if os.name == 'nt' else 'clear')
print ("---------------------------")
print ("| |")
print ("| |")
print ("| Welcome to PyDOS! |")
print ("| |")
print ("| |")
print ("| |")
print ("| |")
print ("| |")
print ("| Version 3.0 |")
print ("| Alpha Edition |")
print ("| |")
print ("| |")
print ("---------------------------")
time.sleep(3)
print ()
print ("-----------------------------------------------")
name = input ("Enter a name: ")
print ("-----------------------------------------------")
print ("Information has been saved.")
print ()
print ("This data will be used in some applications.")
print ("-----------------------------------------------")
time.sleep(3)
while True:
 os.system('cls' if os.name == 'nt' else 'clear')
 print ("-------------------------")
 print ("| |")
 print ("| |")
 print ("| Loading Home |")
 print ("| Screen |")
 print ("| |")
 print ("| |")
 print ("| |")
 print ("| |")
 print ("| |")
 print ("-------------------------")
 time.sleep(1.5)
 os.system('cls' if os.name == 'nt' else 'clear')
 print ("-------------------------------------------------------------------------------")
 print ("| Username:",name," |")
 print ("-------------------------------------------------------------------------------")
 print ("| |")
 print ("| PyDOS Home Screen - Type in an app below. |")
 print ("| |")
 print ("| Apps: |")
 print ("| |")
 print ("| ChangeName |")
 print ("| Shutdown |")
 print ("| SimpleCalc |")
 print ("| PyWrite |")
 print ("| About |")
 print ("| |")
 print ("| |")
 print ("| |")
 print ("| PyDOS Version 3.0 Alpha (Alpha 1.2 |")
 print ("-------------------------------------------------------------------------------")
 selection = input("Select An App: ")
 command_actions = {
 'ChangeName' : ChangeName,
 'SimpleCalc' : simplecalc,
 'Shutdown' : shutdown
 }
 if selection in command_actions:
 action = command_actions[selection]
 action()
 else:
 error_message()

• rolfl: What you may and may not do after receiving answers
• Snowbody: I still don't understand why you think the sleep is necessary at all. It objectively makes for a worse user experience.
• jsanc623: That's a whole boatload of print statements. Why not have a echo() function that accepts a list instead, and each element of that list is a line to print? Something like this: gist.github.com/jsanc623/ad1319b4a5bf6db34469 but that also handles padding and alignment, so you don't have to pass in padding.
• PyxlWuff: The reason why there is sleep is because I am moving away from the 'DOS' thing now. See my answer for details.

Answer 1

time.sleep(2.5)

Again, don't sleep your program, it makes it unnecessarily slow, and it doesn't even act like an old machine would because when it does run, it runs quite fast.

---

--------------------------
| |
| Welcome to SimpleCalc |
| |
| A = Add |
| M = Multiply |
| S = Subtract |
| D = Divide |
| Q = Quit |
| |
--------------------------

You prompt for a capital "A", but only accept a lowercase "a":

if choice == 'a':
 calc_a()

You can easily change this to accept both like this:

choice = input ("| Choice: |").lower()

If you want to accept any input that starts with an "A" or "a", just append [0] to the line.

Your various calc_x() functions are extremely similar. You can reduce some of that similarity by either passing them an argument or using a function to input the values. Personally, if you are not going to accept entire equations and handle order of operations, I would use one function:

def calc(operation):
 print ("----------------------------------")
 num1 = int(input("Enter a number: "))
 num2 = int(input("Enter a number: "))
 print ("----------------------------------")
 if operation == 'a':
 answer = num1 + num2
 elif operation == 's':
 answer = num1 - num2
 elif operation == 'm':
 answer = num1 * num2
 elif operation == 'd':
 answer = num1 / num2
 print ("Your answer is:" ,answer)
 print ("----------------------------------")
 end()

Then, call this function from simplecalc like this:

if choice in "asmd":
 calc(choice)
else:
 print ("Invalid specifacation.") // "specification"

---

Don't call end(), or any other functions, from your calc() function. Actually, you shouldn't even print from your calc() function - what if you want to calculate something and not print it? Also, inputting values is not part of the calculation. I would write this like this (extraneous output removed for simplicity):

def calc(operation, num1, num2):
 if operation == 'a':
 return num1 + num2
 elif operation == 's':
 return num1 - num2
 elif operation == 'm':
 return num1 * num2
 elif operation == 'd':
 if num2 == 0:
 raise ValueError('Divide by 0 expection')
 return num1 / num2
 else:
 raise ValueError('Unknown error')
def simplecalc():
 print ("Welcome to SimpleCalc! You have the following operators:")
 print ("A: Add")
 print ("S: Subtract")
 print ("M: Multiply")
 print ("D: Divide")
 print ("Q: Quit")
 choice = input ("Choice: ").lower()[0]
 if choice == 'q':
 end_simple_calc()
 return
 if choice not in "asmd":
 print ("Invalid specification.")
 end_simple_calc()
 return
 try:
 num1 = int(input("Enter a number: "))
 num2 = int(input("Enter a number: "))
 print ("Your answer is:", calc(choice, num1, num2))
 except ValueError as err:
 print(err.args)
 end_simple_calc()

This not only catches the invalid division by 0 operation, it also catches when you input an invalid number and prints an error message instead of the printing stack trace and crashing.

---

Right here, you only allow three apps; why are the other two in the prompt list?

command_actions = {
'ChangeName' : ChangeName,
'SimpleCalc' : simplecalc,
'Shutdown' : shutdown
}

---

You should be consistent in your naming:

def ChangeName():
def shutdown():

I believe the PEP8 standard states you should use snake_case names.

Also related to naming: def end(). What does end() do? It prints a conclusion to SimpleCalc, but does not show that in the name. What if I was looking through your code adding a new feature, and I saw that in SimpleCalc? I might add it to the end of my new feature and have a problem.

Answer 2

I think that the functions for SimpleCalc should be put in their own module or their own class - presumably you'll want to add more commands at some point, and a function called end is a bit generic as a name.

Your naming conventions in general could be improved - instead of calc_d, call it divide, for instance.

For the SimpleCalc main function, consider adding a loop until the user selects quit, so they can do more than one calculation.

Instead of having a static list of available commands, maybe loop through the keys of your command_actions dictionary.