Develop Reference

Why does using loop-only functions in a def section not work, even when in a loop?

I am making a small text-based game in Python. It involves many inputs and so to avoid bugs, there are a few things I have to check every time an input exists. Naturally, to speed up the process I wanted to put the code into a def in order to simplify the writing process. When I put the code in the def, it red underlines the continue and break commands (meaning they are incorrect), and if you run the code using the def name, a Traceback occurs. I have tried putting the def section at the beginning of the program, after the while True: (The program is supposed to run infinitely until a certain action is taken that breaks the loop) I have also made sure to try putting it under any variables referenced and in the loop so that no part of it is not defined and so that everything would work if I were to just put the code in there.
Here is the code I am trying to put into a def.
def input_bugs():
if letter_one.lower() == "done" and total_count == 0:
print("You have to play at least one game!")
continue
elif letter_one.lower() == "done":
break
elif len(letter_one) > 1:
print("Sorry, you gotta pick a single letter, no more. Otherwise, type 'done' to end the game and see your stats.")
continue
Here is the Traceback I get every time I try to run it.
line 20
continue
^^^^^^^^
SyntaxError: 'continue' not properly in loop
At this point, I don't even care if I have to write it out every time, I can just copy and paste. I am simply curious as to why it doesn't work so that I know in the future. In case you could not tell, I am pretty new to programming so I want to learn from any mistake I make. Also sorry if I referred to some things in the wrong way. Hopefully, you understood what I meant.

Not executing the code outside of the while loop after the break statement

I'm trying to exit an infinite loop but I'm stuck in it. I've tried using the break statement in different ways but the result is always the same: the program terminates after exiting the loop and it doesn't perform the rest of the code. What should I change in the code to solve this problem?
moylist = []
import copy
while True:
thing = input()
if thing == '':
break
moylist.append(thing)
moylist.insert(-2, 'and')
moynovlist = copy.deepcopy(moylist)
moynovlist1 = moynovlist[-2:] # cutting the end
perv = str(moynovlist1)
perv1 = perv[:4] + perv[4:] #without the comma (and ...)

The code is running fine! The reason you think it is exiting the whole program instead of just the while loop is because you don't have any print statements. Simply add, print(perv1) at the end of your program and you'll see that perv1 changes, meaning the loop was exited properly.

How to implement an asynchronous function in python 3

I'm very new to programming as a whole. Had some basic experience with C++ and HTML, like simple calculators and other really basic stuff(I started learning on my own a few months ago) and because of this I'm not even sure if I am posting this question correctly. Maybe it goes without saying but I am new to stackoverflow as well(My first post!), so I may do some things wrong here and I kindly ask for your comprehension. Any constructive criticism is more than welcome!
So here's my problem: I am trying to make a simple chatting program in Python 3, but here's the catch: I want to use python's asychronous capabilities to allow the user to terminate the program at any given time the esc key is pressed. I've looked into a few libraries already, such as pynput, asyncio, tornado and getch(). But no matter how I change my code I just can't seem to reach my goal here.
I made an async function called runalways() that's supposed to run during the entire duration of the program, parallel to the other functions. But it doesn't and I couldn't figure out why...
I'm sorry if I couldn't explain my issue properly. Some terms and concepts are still rather blurry to me, but hopefully it won't be so for long. I'll leave the code I have so far which does a good job implementing the chat function, but that's about it. The async bit is basically inexistent at this moment.
It would be really appreciated if someone could explain what I'm missing:
import time, asyncio
from msvcrt import getch
# Creates a chat-like effect
def typing(text):
for i in text:
print(i, end=" ")
time.sleep(0.1)
time.sleep(1.0)
# Terminates the program
def termination():
print("Program terminated")
time.sleep(0.5)
SystemExit
# Defines async function to read pressed keys and terminate if Esc is pressed
# (Not working)
async def runalways():
while True:
print(ord(getch()))
key = ord(getch())
if key == 27: # Esc
termination()
# Initialize chatting
def startChat():
typing("\nHello!\n")
typing("How are you?\n\n")
typing("Answer:\t")
x = input()
typing("\nAnyways, that isn't relevant right now.\n")
time.sleep(0.5)
typing("Can we get started?\n\n")
typing("Answer(Y/N):\t")
x = input()
# validates input
while (x != "Y") & (x != "N"):
typing("\nHey, don't go fooling around now. Keep it real! Try again.\n\n")
typing("Answer(Y/N):\t")
x = input()
if (x == "Y") | (x == "y"):
typing("\nThere you go! Now, let's go through the basics...\n\n")
termination()
elif (x == "N") | (x == "n"):
typing("\nSorry to hear that... See you next time, then!")
termination()
# Defines starter point for the program
def main():
runalways()
startChat()
main()
I will try my best to clarify any questions that may help the understanding of my issue. Thanks in advance!

You have two functions competing to grab the input. runalways wants to grab them with getch, while your main chat loop is trying with input. The two processes conflict; only one can consume each character. Whenever one thread grabs input, the other gets to claim the buffer for the next input.
Instead, you need to set up a single input channel that terminates immediately on ESC; otherwise, it echoes to the terminal and passes the character to the main loop (or buffers it until EOL appears).

Exiting a python application for 'GAME OVER'

I would like to know why this code does not work; it should exit at the "GAME OVER" point, but it continues to my next defined function.
I have tried other variations on exit() such as: sys.exit(), quit() and SystemExit.
run_attack = input("What do you do: Run/Attack\n")
run = ['run', 'Run', 'RUN']
attack = ['attack', 'Attack', 'ATTACK']
run_attack = 1
while run_attack < 10:
if run_attack == ("run") or ("Run") or ("RUN"):
print ("You turn to run from the wolf but he quickly pounces
you...")
time.sleep(2)
print("You are quickly ripped apart and just about get to see
yourself be eaten.")
print("GAME OVER")
break
exit() #This is where the game should exit, yet after input it
continues to the next function
elif run_attack == ("attack") or ("Attack") or ("ATTACK"):
print("You brace yourself for a bite and have no time to reach"
"for any kind of weapon form your backpack.")
time.sleep("2")
input("You clock the dog hard, twice on the muzzle.")
print("The dog recoils in pain and retreats back to the woods.")
print("You quickly start running as you assume there will be a den in the woods.")
break
else:
input("Type Run or Attack...")

You have several problems in your code; why did you write this much without testing it?
First, you read the user's input, immediately replace is with 1, and then try to test it (incorrectly) as if it were still a string. Your posted code has several syntax errors, so I have some trouble reproducing the problem. However, the immediately obvious problem is here:
break
exit() # This is where ...
You can't get to the exit statement, as you break from the loop just before you can get there.
I strongly recommend that you back up to a few lines and use incremental programming: write a few lines at a time, debug those, and don't continue until they do what you want.
Also look up how to test a variable against various values. Your if statement is incorrect. Instead, try the list inclusion you're trying to set up:
if run_attack in run:
...
elif run_attack in attack:
...

I took the liberty of rewriting your whole program to show you a few things wrong with it and a few tricks. I've done it without the loop, since you never use it anyway... you can add the while loop later once you've mastered it, but you should really go back to basics on some things here:
run_attack = input("What do you do: Run/Attack\n")
if run_attack.lower() == "run":
print("""some
stuff
with
multiple
lines and GAME OVER""")
exit()
elif run_attack in ("attack", "Attack", "ATTACK"):
print("""some
stuff
with
multiple
lines""")
else:
input("Type Run or Attack...")
Some notes:
Using """ for strings enables you to write multiple lines without multiple print statements
Using str.lower() on strings makes everything easy to compare because you only have to compare it to the lowercase version of each string. However for attack you can notice I used a different inclusion test, without multiple conditions. Either way works here.
Like the other answer here (and many comments), you should use only exit() to leave the program entirely, or only break to exit the loop and continue to other code that's beneath the entire loop.
When you rewrite your loop, with a condition like while number_of_turns < 10 don't forget to add 1 to the number of turns on each loop, otherwise that condition is always True and you'll have an infinite loop...
I'm actually quite surprised this code had any resemblance to the behavior you expected from it, my suggestion is to go back over to the basics of python, learn loops, string methods, basic commands. The rest is already said in the other answer here (which is better than mine, frankly) just wanted to add some ideas.

Exit while loop by user hitting ENTER key

I am a python newbie and have been asked to carry out some exercises using while and for loops. I have been asked to make a program loop until exit is requested by the user hitting <Return> only. So far I have:
User = raw_input('Enter <Carriage return> only to exit: ')
running = 1
while running == 1:
Run my program
if User == # Not sure what to put here
Break
else
running == 1
I have tried: (as instructed in the exercise)
if User == <Carriage return>
and also
if User == <Return>
but this only results in invalid syntax.
Please could you advise me on how to do this in the simplest way possible.
Thanks

I ran into this page while (no pun) looking for something else. Here is what I use:
while True:
i = input("Enter text (or Enter to quit): ")
if not i:
break
print("Your input:", i)
print("While loop has exited")

The exact thing you want ;)
https://stackoverflow.com/a/22391379/3394391
import sys, select, os
i = 0
while True:
os.system('cls' if os.name == 'nt' else 'clear')
print "I'm doing stuff. Press Enter to stop me!"
print i
if sys.stdin in select.select([sys.stdin], [], [], 0)[0]:
line = raw_input()
break
i += 1

Actually, I suppose you are looking for a code that runs a loop until a key is pressed from the keyboard. Of course, the program shouldn't wait for the user all the time to enter it.
If you use raw_input() in python 2.7 or input() in python 3.0, The program waits for the user to press a key.
If you don't want the program to wait for the user to press a key but still want to run the code, then you got to do a little more complex thing where you need to use kbhit() function in msvcrt module.
Actually, there is a recipe in ActiveState where they addressed this issue. Please follow this link
I think the following links would also help you to understand in much better way.
python cross platform listening for keypresses
How do I get a single keypress at a time
Useful routines from the MS VC++ runtime
I hope this helps you to get your job done.

Use a print statement to see what raw_input returns when you hit enter. Then change your test to compare to that.

This works for python 3.5 using parallel threading. You could easily adapt this to be sensitive to only a specific keystroke.
import time
import threading
# set global variable flag
flag = 1
def normal():
global flag
while flag==1:
print('normal stuff')
time.sleep(2)
if flag==False:
print('The while loop is now closing')
def get_input():
global flag
keystrk=input('Press a key \n')
# thread doesn't continue until key is pressed
print('You pressed: ', keystrk)
flag=False
print('flag is now:', flag)
n=threading.Thread(target=normal)
i=threading.Thread(target=get_input)
n.start()
i.start()

You need to find out what the variable User would look like when you just press Enter. I won't give you the full answer, but a tip: Fire an interpreter and try it out. It's not that hard ;) Notice that print's sep is '\n' by default (was that too much :o)

if repr(User) == repr(''):
break

a very simple solution would be, and I see you have said that you
would like to see the simplest solution possible.
A prompt for the user to continue after halting a loop Etc.
raw_input("Press<enter> to continue")

user_input=input("ENTER SOME POSITIVE INTEGER : ")
if((not user_input) or (int(user_input)<=0)):
print("ENTER SOME POSITIVE INTEGER GREATER THAN ZERO") #print some info
import sys #import
sys.exit(0) #exit program
'''
#(not user_input) checks if user has pressed enter key without entering
# number.
#(int(user_input)<=0) checks if user has entered any number less than or
#equal to zero.
'''

Here is the best and simplest answer. Use try and except calls.
x = randint(1,9)
guess = -1
print "Guess the number below 10:"
while guess != x:
try:
guess = int(raw_input("Guess: "))
if guess < x:
print "Guess higher."
elif guess > x:
print "Guess lower."
else:
print "Correct."
except:
print "You did not put any number."

You are nearly there. the easiest way to get this done would be to search for an empty variable, which is what you get when pressing enter at an input request. My code below is 3.5
running = 1
while running == 1:
user = input(str('Enter <Carriage return> only to exit: '))
if user == '':
running = 0
else:
print('You had one job...')

I recommend to use u\000D. It is the CR in unicode.

Here's a solution (resembling the original) that works:
User = raw_input('Enter <Carriage return> only to exit: ')
while True:
#Run my program
print 'In the loop, User=%r' % (User, )
# Check if the user asked to terminate the loop.
if User == '':
break
# Give the user another chance to exit.
User = raw_input('Enter <Carriage return> only to exit: ')
Note that the code in the original question has several issues:
The if/else is outside the while loop, so the loop will run forever.
The else is missing a colon.
In the else clause, there's a double-equal instead of equal. This doesn't perform an assignment, it is a useless comparison expression.
It doesn't need the running variable, since the if clause performs a break.

If you want your user to press enter, then the raw_input() will return "", so compare the User with "":
User = raw_input('Press enter to exit...')
running = 1
while running == 1:
Run your program
if User == "":
break
else
running == 1

The following works from me:
i = '0'
while len(i) != 0:
i = list(map(int, input(),split()))