Is there anyway for python 3 to recognise a keypress? For example, if the user pressed the up arrow, the program would do one thing whereas if the down arrow was pressed, the program would do something else.
I do not mean the input() function where the user has to press enter after the keypress , I mean where the program recognises the keypress as some as it was pressed.
Is this question too confusing? xD
Python has a keyboard module with many features. You Can Use It In Both Shell and Console.
Install it, perhaps with this command:
pip3 install keyboard
Then use it in code like:
import keyboard #Using module keyboard
while True: #making a loop
try: #used try so that if user pressed other than the given key error will not be shown
if keyboard.is_pressed('up'): #if key 'up' is pressed.You can use right,left,up,down and others
print('You Pressed A Key!')
break #finishing the loop
else:
pass
except:
break #if user pressed other than the given key the loop will break
You can set it to multiple Key Detection:
if keyboard.is_pressed('up') or keyboard.is_pressed('down') or keyboard.is_pressed('left') or keyboard.is_pressed('right'):
#then do this
You Can Also Do Something like:
if keyboard.is_pressed('up') and keyboard.is_pressed('down'):
#then do this
It Also Detect Key For The Whole Windows.
Thanks.
I assume this is a gui program,
If using the built-in gui module Tkinter, you can use bind to connect a function to a keypress.
main.bind('<Up>', userUpkey)
Where userUpKey is a function defined in the current scope.
Related
I tried this
from msvcrt import getch
while True:
key = ord(getch())
if key == 27: #ESC
print("You pressed ESC")
elif key == 13: #Enter
print("You pressed key ENTER")
but it works only in terminal, i want to run a function whenever user presses the key, even his curser in not in terminal, Please help...
Thank you!
What you're trying to do is not the easiest thing if you want to get it working correctly. If you have a window/widget in focus, using Qt and a QKeyEvent would be the easiest solution. However, if you want your input to be read globally/in other applications and not just from the terminal, you'll need to do something a bit more involved:
How to generate keyboard events in Python?
I have been facing this problem for the last week,I thought it would be trivial but after trying many different approaches I don't know what else to try.
I have an application where I need to have key detection (to move a robot arm with the keyboard) but when I press enter I need to add some inputs, which should be as long as I want, just some normal input("insert here").
I know about the python libraries to get key detection, I got pynput to work successfully but it crashes my raspberry pi when I start and stop the threads a few times,I tried the Keyboard library but the whole root requirement is a let down, I also got curses to work and this seems to be solid and is (almost) not causing any issues, so detecting 1 key is not a problem.
I of course know how to name my files and get all the information that I need by doing input(), so if I had to use one of those options the job would be rather simple, the challenge comes when I try to apply both approaches together, basically detect the keys to do everything I need, and use python Input to get all the inputs from the user as soon as enter is pressed, all the libraries to detect key seems to take full control and they don't want to release it without a fight. They seem to expect the user to always require single key detection but in my case I would need to constantly turn it on and off, I couldn't figure out any efficient (or not) way to get it to work properly.
My question is:
What is the best approach to have key detection + full user input when needed with curses (or any alternative) in a non blocky way (as my code need to do some other things while listening for keys), is creating and destroying the whole thing the only alternative?
This is my current test code that I created for simplicity (which works but blocks everything while listening for keys):
import curses
import time
import os
stdscr = None
addInput = False
def SetupCurses():
global stdscr
stdscr = curses.initscr()
curses.cbreak()
stdscr.keypad(1)
def StartCurse():
global addInput
key = ''
while key != ord('q'):
key = stdscr.getch()
stdscr.addstr(str(key))
if key == ord('a'):
print("\nyou pressed a\n")
if key == 10:
print("\nyou pressed enter!\n")
addInput = True
break
def EndCurse():
curses.endwin()
while(True):
SetupCurses()
StartCurse()
EndCurse()
if addInput:
theinput = input("add your input\n")
print(theinput)
time.sleep(4)
addInput = False
#if there isn't any input to add I want the code to continue because there is non-related keys stuff to do, but of course it stopped at "StartCurse"
#if there is something to add the code can stop at addInput
The reason for the loop is because the user can save as many positions as he want, so after adding some inputs the possibility of adding more is there.
I saw people making this non-blocking by closing the curses loop after a few seconds (which stops everything anyway...) kind of getting the input by luck...something like:
def ExecuteCurses():
global AddInput
#open it and close it very quickly to grab a key if it is pressed
c = stdscr.getch()
if c == ord('a'):
print("you pressed a")
AddInput = True
time.sleep(1)
curses.endwin()
If you want a full and long user input you will need to use the curses.echo() and then use the stdscr.getstr(). That will wait for the user to press enter().
And to not block the program while getting input you need threading which you will have to import at the top of your program
And for the threading here is a link so you can find out more about threading.
I hope it answers your question
I would like to know how to get user input in python without using the command line or an input box.
Let me explain. I do not want to do this
#All code is python 3
name=input("What is your name?")
Why? When running scripts, the command line is not auto-focused. Furthermore, it pops up another window, something I do not want because I can't hit escape to close it in a hurry (Something which you may want to do if you're playing a game).
What have I tried?
I looked at WX and it's dialog function, something like this:
import wx
app=wx.App()
def text_entry(title,message):
result=None
dlg=wx.TextEntryDialog(None, message,title)
if dlg.ShowModal()==wx.ID_OK: result=dlg.GetValue()
dlg.Destroy()
return result
text_entry("Text entry","Enter something here")
While this works, it pops up another window which again, I do not want. However, it is closer to what I am ultimately looking for, because I can hit escape to make it go away.
I have tried using pygame and it's key.get_pressed() function, but it inserts a lot of the same letter into the entry, even if I gently tap the key. Also, when I implemented it into the project, it can only pick up on normal letters. Writing 26 if statements to detect key presses for a single letter with or without the shift key seems a little counter intuitive.
Finally, I am a bit hesitant to try tkinter. I happen to be blind, and from what I read, tk is very visual, which makes me concerned that it won't play nicely with my screen reader (NVDA).
So, I'm here. After searching on google for "getting input without using command line in python 3", "input in the same window", and "input without using input()" yielded nothing.
To recap, I want to accept user input without using the input() function, and without any additional windows popping up for the duration of me doing so.
Thank you.
What about this solution using the msvcrt module. At any time if you press escape then the program will exit. Python sys.exit(), and built-ins exit() and quit() all call raise SystemExit so this is just one less call to perform. If you press the enter or return key then the while loop ends and you can use the keys that were pressed later in your program as they are stored in the variable user_input. The print at the end just proves that the pressed keys are stored in user_input variable and the input() function simply to leave the window open so you can see it working.
import msvcrt
user_input = b''
while True:
pressed_key = msvcrt.getche() # getch() will not echo key to window if that is what you want
if pressed_key == b'\x1b': # b'\x1b' is escape
raise SystemExit
elif pressed_key == b'\r': # b'\r' is enter or return
break
else:
user_input += pressed_key
print('\n' + user_input.decode('utf-8')) # this just shows you that user_input variable can be used now somewhere else in your code
input() # input just leaves the window open so you can see before it exits you may want to remove
So after doing some more research, I found this:
https://codeload.github.com/Nearoo/pygame-text-input/zip/master
I think this is what I am looking for, though it still needs to be slightly modified. Thank you for the assistance
I want to make Python execute my command when a key is pressed.
Like if "a" is pressed, the output should be:
A is pressed
or like it asks you to press key "a" and if you press it, its output should be Thanks for pressing the key! We are processing!
Sorry if I'm not clear, I'm actually not english
Assuming you don't need this to work when the window is not in focus, you should use getch from msvcrt to react to the keypresses immediately and then if and elif to distinguish the keys. I'd also recommend normalizing the case of the keys with upper or lower:
import msvcrt
while True:
key = msvcrt.getch().lower()
if key == b'a':
print("You've pressed A. I'll now do the thing I'm supposed to do when you press A.")
elif key == b'q':
print("Quitting...")
break
else:
print("You've pressed a key I don't know how to handle! PANIC!")
On Windows, you can call msvcrt.getch() to get the character of a single key press.
>>> import msvcrt
>>> msvcrt.getch()
b'a'
If using Windows OS, you can use msvcrt module as explained in other answers.
Or, you can simply get user input and check if it is corresponding key.
key = input('press key')
if key == 'a':
print('a is pressed')
But, user must press enter after the key.
Third option would be to use GUI library like Tkinter. Check this short tutorial for Events and Bindings in Tkinter.
You need some module that can handle key or mouse events. Depending what you want to achieve you can use for example Tkinter or even Pygame
Is there a way to program a function that takes user input without requesting it? For example, during a game of tic-tac-toe, the user could press "Q" at any time and the program would close?
There are a few ways to do this, and they are all different.
If your game is a terminal application using curses, you would catch the q when you call getch(), and then raise SystemExit or simply break out of your while loop that many curses applications use.
Using tkinter or another GUI library, you would bind a key press event to your Frame widget that holds the tic-tac-toe board.
Assuming you are just printing the board out (I have a basic Tic-Tac-Toe game that does that), during input you could close it (even though you specifically asked otherwise):
user_option = input("Enter a space to move to, or 'Q' to quit: ")
try:
if user_option.lower() == 'q': # makes everything lowercase so it is easier to handle
import sys
sys.exit("Game Terminated.")
except TypeError:
# other code
I'm not sure how the player chooses to move, so I used try and except. In my Tic-Tac-Toe game, I have the user input an integer, which corresponds to a space on the board.
Or, you can just have the user press Ctrl+C which is the automatic KeyBoardInterrupt in Python (ends the program).