Guess the computer's number using functions

Question

I am looking to improve the Python Number Guessing Game program:

1. How is the overall structure of the code?

2. Have I used functions to the best of their ability?

3. Can the code be simplified? If yes, please feel free to show how.

4. The replay_game() function especially seems un-pythonic and overkill.

# Guess My Number Game
# MacOSX (Latest), Python 3.4.3, 27/08/2017
# Guess The Computers number between 1-100
from random import randint
from time import sleep
def gen_number():
 random_number = randint(0, 101)
 return random_number
def intro():
 print("Welcome to, Guess My Number!")
 print("Simply guess the number between 1-100 that the Computer is 'thinking' of!")
 print()
def ask_number(question, random_number):
 response = None
 while response != random_number:
 try:
 response = int(input(question))
 if response > random_number:
 print("Lower... ")
 elif response < random_number:
 print("Higher... ")
 else:
 correct = response
 congrat_winner(correct, random_number)
 except ValueError:
 print("Invalid. Enter a number between 1-100 ")
 return response
def human_guess():
 print("Ok Human! Let's begin... ")
 sleep(1)
 random_number = gen_number() # Named the variable random_number, the same as the variable in gen_number(). Is this good practise?
 guess = ask_number("Guess the number: ", random_number)
def congrat_winner(correct, random_number):
 if correct == random_number:
 print()
 print("Calculating results...")
 sleep(1)
 print()
 print("WELL DONE!")
 print("The answer was indeed,", str(correct) + "!")
def replay_game():
 replay_question = None
 while replay_question != 'y' or 'n':
 replay_question = input("Would you like to play again (y/n)? ").lower()
 if replay_question == 'y':
 print()
 print("Rebuilding game... ")
 main()
 elif replay_question == 'n':
 print("Goodbye!")
 exit()
 else:
 print("please enter either 'y' or 'n'... ")
def main():
 intro()
 human_guess()
 replay_game()
main()

Answer 1

There is a classic problem in this condition:

while replay_question != 'y' or 'n':

It always evaluates to True since string n is always truthy.

And, here is a set of code style violations I would work on:

• guess variable inside the human_guess() function is unused
• keep 2 blank lines between the function definition (PEP 8 - Style Guide)
• put the main() function call into under the if __name__ == '__main__':
• the print("Invalid. Enter a number between 1-100 ") is overly indented with 8 spaces, use 4 spaces

• you can use a multi-line string for your intro message:

  print("""
  Welcome to, Guess My Number!
  Simply guess the number between 1-100 that the Computer is 'thinking' of!
  """)
  

• Aemyl: while replay_question not in ('y', 'n'):
• Greg: Hi there, many thanks for your answer. Was the while loop in replay_question just comparing two string types instead of the content of the strings?
• LyricLy: @Greg If you split up the conditional, you get replay_question != 'y' and 'n'. Since non-empty strings in Python are always truthy, this condition always evaluates to true.
• Greg: @lyricLy Brilliant, thank you for confirming. Greg.

Answer 2

Just some notes:

---

The bug:

random_number = randint(0, 101)

returns integers from 0 to 101, including both 0 and 101. The fix:

random_number = randint(1, 100)

(but see the next note).

---

The magic numbers 1 and 100, moreover repeatedly used. You may define them as constants near the top of your code, e. g.

LOWER_LIMIT = 1
UPPER_LIMIT = 100

and then use them in these (inconsecutive) lines of your code:

random_number = randint(0, 101)
print("Simply guess the number between 1-100 that the Computer is 'thinking' of!")
print("Invalid. Enter a number between 1-100 ")

changing them to

random_number = randint(LOWER_LIMIT, UPPER_LIMIT) # see fix in the first note
print("Simply guess the number between {}-{} that the Computer is 'thinking' of!"
 .format(LOWER_LIMIT, UPPER_LIMIT))
print("Invalid. Enter a number between {}-{} "
 .format(LOWER_LIMIT, UPPER_LIMIT))

( {} in strings are replacement fields for parameters in the .format() method.)

• Greg: Wow! I haven't been exposed to this sort of formatting before in Python. I really like this. Thank you for pointing it out. In addition, it is far easier to understand when you used the constant variables. Out of interest, do you think I could have put the main() function to better use? Thank you. Greg
• MarianD: We still learn something new. In Python 3.6+ is even possible to write it more straighforward, without .format() method, with the f string's prefix and expressions directly in the replacement fields {}- print(f"Invalid. Enter a number between {LOWER_LIMIT}-{UPPER_LIMIT} ")
• MarianD: It's definitely better to use the main() function - see the last (3rd) part of my another answer with the links for reasoning such practice.

Answer 3

Your answers (Lower... or Higher... ) are ambiguous - is the answer (guess) lower or is such the unknown number?

Maybe something as "Try lower ..." would be more appropriate.

---

In your congrat_winner() function

def congrat_winner(correct, random_number):
 if correct == random_number:
 print()
 print("Calculating results...")
 sleep(1)
 print()
 print("WELL DONE!")
 print("The answer was indeed,", str(correct) + "!")

is the introductory testing superfluous (and - consequently - the second parameter is needless) as you call that function only after passing the similar test.

So your function may be shortened to

def congrat_winner(correct):
 print()
 print("Calculating results...")
 sleep(1)
 print()
 print("WELL DONE!")
 print("The answer was indeed,", str(correct) + "!")

Subsequently, the part

 else:
 correct = response
 congrat_winner(correct, random_number)

where you call that function have to be changed to

 else:
 congrat_winner(response) # directly used 'response' instead of 'correct'

(There is no more reason for the correct = response statement.)

• Greg: Excellent. Thank you for your feedback. Yes, the if statement in congrat_winner() was useless. Would it be simpler to call the congrat_winner function through human_guess by using the guess variable? Thank you.
• MarianD: No, it isn't possible as guess is only a local variable of the human_guess, btw. never used so you may simply omit it. To be clear I am going to write another answer about it.

Answer 4

I would replace random_number = gen_number() with randint(0, 101).

randint is already a function. What is the use in wrapping it in another function which does nothing extra?

• Greg: Thank you for your answer. I have edited my question to show improved code.

Answer 5

In the loop where you take input you have the following statement:

 try:
 response = int(input(question))
 if response > random_number:
 print("Lower... ")
 elif response < random_number:
 print("Higher... ")
 else:
 correct = response
 congrat_winner(correct, random_number)
 except ValueError:
 print("Invalid. Enter a number between 1-100 ")

If the input is not numeric, you return Invalid. Enter a number between 1-100, but not when your input is outside of the 1-100 range. You might want to add a check for that as well:

 try:
 response = int(input(question))
 if response not in range(1, 101):
 print("Invalid. Enter a number between 1-100 ")
 elif response > random_number:
 print("Lower... ")
 elif response < random_number:
 print("Higher... ")
 else:
 correct = response
 congrat_winner(correct, random_number)
 except ValueError:
 print("Invalid. Enter a number between 1-100 ")

• Greg: Hi - thank you, I just spotted this - I have added the new code in the question section above. Greg.

Answer 6

In the last line of your human_guess() function

 guess = ask_number("Guess the number: ", random_number)

you assign the return value of the function ask_number() to a local variable guess which is not accessible from outside of the human_guess() function, so it may be omitted.

So that statement will become just:

ask_number("Guess the number: ", random_number)

Consequently your ask_number() function need not return anything so the last line in its definition

 return response

may be safely deleted, too.

• Greg: Great - thank you. I have taken your advice onboard and have updated the code accordingly in the question section.

Answer 7

I have collated and considered all the fantastic answers above and greated the following program. I hope this is of significant use.

# Guess My Number Game
# MacOSX (Latest), Python 3.4.3, 28/08/2017
# Guess the Computers number between 1-100
from random import randint
from time import sleep
import sys
LOWER_LIMIT = 1
UPPER_LIMIT = 100
def intro():
 print("""
 Welcome to, Guess My Number!
 Simply guess the number between {}-{} that the Computer is 'thinking' of!
 You will have the option of replaying the game. First, guess the number!
 Ok Human, let's begin... """
 .format(LOWER_LIMIT, UPPER_LIMIT
 ))
 sleep(1)
def ask_number(question, random_number):
 response = None
 while response != random_number:
 try:
 response = int(input(question))
 if response not in range(LOWER_LIMIT, UPPER_LIMIT):
 print("Invalid. Enter a number between {}-{} "
 .format(LOWER_LIMIT, UPPER_LIMIT))
 elif response < random_number:
 print("Try Higher... ")
 elif response > random_number:
 print("Try Lower... ")
 else:
 congrat_winner(response)
 except ValueError:
 print("Invalid. Enter a number between {}-{} "
 .format(LOWER_LIMIT, UPPER_LIMIT))
def human_guess():
 random_number = randint(LOWER_LIMIT, UPPER_LIMIT)
 ask_number("Guess the number: ", random_number)
def congrat_winner(winning_guess):
 print()
 print("Calculating results...")
 sleep(1)
 print("CONGRATULATIONS")
 print("The answer was indeed,", str(winning_guess) + "!")
def replay_game():
 replay_question = None
 while replay_question not in ('y', 'n'):
 replay_question = input("Would you like to play again (y/n)? ").lower()
 if replay_question == 'y':
 print("Rebuilding game... ")
 sleep(1)
 main()
 elif replay_question == 'n':
 print("Goodbye... ")
 break
 else:
 print("please enter either 'y' or 'n'... ")
def main():
 intro()
 print()
 human_guess()
 print()
 replay_game()
 print()
 return 0 
if __name__ == '__main__':
 sys.exit(main())