Exit while loop by user hitting ENTER key

Question

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  lt Return gt  only  So far I have   User   raw input  Enter  lt Carriage return gt  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     lt Carriage return gt    and also  if User     lt Return gt    but this only results in invalid syntax  Please could you advise me on how to do this in the simplest way possible   Thanks

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

if repr User     repr          break

User · Answer

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

User · Answer

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  lt Carriage return gt  only to exit           if user                running   0     else          print  You had one job

User · Answer

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

User · Answer

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

User · Answer

user input input  ENTER SOME POSITIVE INTEGER      if  not user input  or  int user input  lt  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  lt  0  checks if user has entered any number less than or   equal to zero

User · Answer

The following works from me   i    0  while len i     0      i   list map int  input   split

User · Answer

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

User · Answer

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  lt  x              print  Guess higher           elif guess  gt  x              print  Guess lower           else              print  Correct       except          print  You did not put any number

User · Answer

Here s a solution  resembling the original  that works   User   raw input  Enter  lt Carriage return gt  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  lt Carriage return gt  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

User · Answer

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 lt enter gt  to continue

[python] Exit while loop by user hitting ENTER key

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