Python: Why Does my while loop keep looping

Question

def guess():
 while True:
 try:
 guess = raw_input("Guess your letter")
 if len(guess) != 1 or guess.isdigit() == True:
 print "Please guess again"
 if len(guess) == 1 and guess.isdigit() == False:
 guessed.append = guess
 return guess
 break
 except StandardError:
 pass
print guess()

this loop keeps repeating no matter what value I put in the raw input. Why???

• Paul: probably because guessed.append = guess raises an error. Can't be sure because you don't tell us what guessed is
• Henry Keiter: Other people have diagnosed your problem already, but it's probably worth noticing that your break statement is unreachable (and therefore worthless).
• TehTris: try,except statements often hide real errors. Why are you using one? it seems like you already have error catching in the form of your if statements?

Answer 1

Because guessed.append = guess wil raise an error every time len(guess) == 1 and guess.isdigit() == False is True and then the control will go to the except block which is going to restart the loop again.

If you've defined guessed somewhere in your code then I think you probably wanted to do this:

guessed.append(guess)

Otherwise define guessed first.

Answer 2

Every time you try to execute the line guessed.append = guess you raise a StandardError, so the line telling you to return guess is never executed.

To fix it you should define guessed outside the function, and correct the line to guessed.append(guess).

Also note that the line break right after return guess would never be executed even if you fixed this bug.