In my first month of learning python, I wrote a simple guess the number game. It did not include exception handling, was not pep8 compliant, and was organized somewhat poorly. It also needed updating because it used what I like to call "C Print Formatting," which used to be correct in python but is now being replaced. http://www.python.org/dev/peps/pep-3101/ discusses why. I decided to include a little of my coding process in this post as a way to pre-empt debugging.
The following code example was my first iteration. I knew that the user would be making multiple guesses, so my prompt for guess had to be a separate function called multiple times. I also included exception handling with my prompt so that the guess had to be a number within range and not a letter. I didn't know yet if generating the random integer would be complicated, so I hard coded a value for the correct answer and had the program print when completed, so I knew if the program reached the final step. In this version, you get one guess and the program doesn't know if you are wrong or right.
minm = 1
maxm = 20
max_guesses = 6
def randomize():
return 4
def prompt_for_guess():
try:
message = "Guess a number between {:d} and {:d} \n"
guess = int(raw_input(message.format(minm, maxm)))
if guess not in range(minm, maxm + 1):
return prompt_for_guess()
else:
return guess
except ValueError:
print("Must be a number.")
return prompt_for_guess()
def main():
message = "I'm thinking of a number. I'll give you {:d} guesses"
print(message.format(max_guesses))
guess = prompt_for_guess()
answer = randomize()
print("The answer was {:d}".format(answer))
if __name__ == "__main__":
main()
Running the program with inputs of a letter, a number out of range, and a number within range verified that my exception handling worked. At this time, I imported random in my terminal and read the directory and help to review use of randint. Randint includes the last boundary, unlike the built in python range. Because it was only one line of code, I decided it did not need its own function. Also because I only needed to use it one time. My next attempt looked like this:
import random
# configs
minm = 1
maxm = 20
max_guesses = 6
guesses_taken = 1
def prompt_for_guess():
"""Asks for a guess and repeats if input is not a number in range"""
try:
message = "Guess a number between {:d} and {:d}. \n"
guess = int(raw_input(message.format(minm, maxm)))
if guess not in range(minm, maxm + 1):
return prompt_for_guess()
else:
return guess
except ValueError:
print("Must be a number.")
return prompt_for_guess()
def main():
message = "I'm thinking of a number. I'll give you {:d} guesses"
print(message.format(max_guesses))
answer = random.randint(minm, maxm)
if guesses_taken <= max_guesses:
guess = prompt_for_guess()
if guess == answer:
print("That's it! You win!")
break
else:
if answer > guess:
reason = "low"
else:
reason = "high"
print("Your guess is too {:s}".format(reason))
guesses_taken += 1
print("The answer was {:d}".format(answer))
if __name__ == "__main__":
main()
But this had some errors. First, my guesses taken cannot be assigned outside my main function without making it a global variable. Unlike my minm, maxm, and max guesses, I want to edit the value of guesses taken. My second error was using an if statement instead of a while loop for guesses taken less than max guesses. I want my loop to continue until the user exceeds the number of allowed guesses or they get the answer right. My third mistake was my final print statement. It was useful for my initial attempt to write the program, but now I only want to reveal the answer if the user loses.
Now The Final Code
import random
# configs
minm = 1
maxm = 20
max_guesses = 6
def prompt_for_guess():
"""Asks for a guess and repeats if input is not a number in range"""
try:
message = "Guess a number between {:d} and {:d}. \n"
guess = int(raw_input(message.format(minm, maxm)))
if guess not in range(minm, maxm + 1):
return prompt_for_guess()
else:
return guess
except ValueError:
print("Must be a number.")
return prompt_for_guess()
def main():
message = "I'm thinking of a number. I'll give you {:d} guesses"
print(message.format(max_guesses))
answer = random.randint(minm, maxm)
guesses_taken = 1
while guesses_taken <= max_guesses:
guess = prompt_for_guess()
if guess == answer:
print("That's it! You win!")
break
else:
if answer > guess:
reason = "low"
else:
reason = "high"
print("Your guess is too {:s}".format(reason))
guesses_taken += 1
if guesses_taken > max_guesses:
print("The answer was {:d}".format(answer))
if __name__ == "__main__":
main()
