readkey command in python - python

I want my Python program to stop and wait until any key is pressed, then to print the key that was just pressed.
It's like the Pascal's command key := readkey; writeln(key);.
I' ve tried yet to use the msvcrt module and the getch command but it didn' t work. I tried this:
import msvcrt
s = msvcrt.getch()
print (s)
And it didn' t wait I pressed a key, it immediately printed b'\xff' and it ended the program
I' m working with python 3.4
Do you know any way to help me ?

I found out that if I started my .py file from the command line (pythonw) the command msvcrt.getch() didn' t work but if I save my .py file and I launched it, the command msvcrt.getch() worked correctly !

Im not sure this will be usefull for anyone but the answer to this is
s = input()
This will store the input in the "s" variable.

Related

Get user console input before user hitting enter

I have a quite simple problem.
I want to get some console input from a user (without an enter press at the end) and do something with it right away.
I quickly saw that the input() function from python would not work. I thought maybe you could write something like this:
sys.stdout.write("Input: ")
while True:
line = sys.stout.readline()
// Do something with the lines
But unfortunately it does not work because stdout is not readable. With stdin it does not work either because it waits for a enter press of the user.
Is it somehow possible to get lines without the user submit it?
You can get input from console interactively in byte format instead of getting a string with input command.
import sys
while True:
c = sys.stdin.read(1) # Read one byte
Here is what you might be looking for.
To get this working you will need to use pip install keyboard in the command line first.
import keyboard
while True:
key_pressed = keyboard.read_key()
print(f'You pressed {key_pressed}.')

Key press in a Python subprocess?

try:
subprocess.run(exe_path)
keyboard.press_and_release('enter')
print('Successful Extracted')
except Exception as exe:
print(exe.args)
keyboard.press_and_release('enter')
The point is to run the EXE of windows but it needs an input of keyboard to end its process, and it will remain stuck over there unless a keyboard input is given physically. Right now I am facing an issue as
subprocess.run('some_exe')
is running the process and after successfully run asking
Press Any Key To Exit
while I have already mentioned next to subprocess.run
keyboard.press_and_release('enter')
and it's coming to the next line unless we press the button from the keyboard manually
NOTE: python3.8
For the sake of a reproducible example, say we want to run the following Python script as a subprocess, let's call it script.py.
input('Press Enter to exit.')
It won't terminate until the user presses the Enter key. If we want to emulate the key press, we can just send a newline character to the subprocess's stdin using Popen.communicate. Like so:
from subprocess import Popen, PIPE
process = Popen(['python', 'script.py'], stdin=PIPE, text=True)
process.communicate('\n')
The external program doesn't have to be a Python script, it can be any executable. Just replace ['python', 'script.py'] with the corresponding command-line call, e.g. ['some_exe'].
Obviously this also works if the external program accepts any key to exit. Only sending special keys which don't have an obvious text representation, such as F1, would complicate things.
You can create a .vbs file to run your .exe file or python script without console debugging window:
Set oShell = CreateObject ("Wscript.Shell")
Dim strArgs
strArgs = "cmd /c python main.py"
oShell.Run strArgs, 0, false
If you have .exe file just replace python main.py with yourFile.exe.

How do I erase a residual character at prompt after exiting python program

I am writing Python menu programs, and are capturing key strikes (no ) and that's working OK. The problem is when I exit the program using sys.exit() the last keystrike ends up on the command line.
I'm using the 'keyboard' module which required pip install, but I'm open to suggestion on other ways to capture the key strike. I've tried using msvcrt.getch(), sys.stdout.flush(), sys.stdin.flush() before exiting, to no avail. In the code below, the character echoed to the command line is not necessarily upper case, depending on the caps lock.
Thanks in advance. This has to be a common problem, but I've spent a lot of time searching and so far nothing that works.
import keyboard
import sys
key = keyboard.read_key()
key = key.upper()
print('Key pressed: '+key)
sys.exit() # leaves residual character on the command line

PyCharm: msvcrt.kbhit() and msvcrt.getch() not working?

I've tried to read one char from the console in PyCharm (without pressing enter), but to no avail.
The functions msvcrt.getch() stops the code, but does not react to key presses (even enter), and msvcrt.kbhit() always returns 0. For example this code prints nothing:
import msvcrt
while 1:
if msvcrt.kbhit():
print 'reading'
print 'done'
I am using Windows 7, PyCharm 3.4 (the same heppens in idle).
What is wrong? Is there any other way to just read input without enter?
It's possible in a special mode of the Run window.
Check the Emulate terminal in output console setting checkbox in Run/Debug Configurations
You are trying to compare <Class 'Bytes'> to <Class 'string'>.
Cast the key to a string and then compare:
import msvcrt
while True:
if msvcrt.kbhit():
key = str(msvcrt.getch())
if key == "b'w'":
print(key)
To run the program in the Command Line go to: edit Configurations > Execution > enable "Emulate terminal in output console".
This code will fix. So use key.lower()
while True:
key = msvcrt.getch()
if key == "b'w'":
print("Pressed: W without lower()")
#It won't work.
if key.lower() == "b'w'":
print("Pressed: W with lower()")
#This one will work.
#I don't know why but key.lower() works.

Python, Press Any Key To Exit

So, as the title says, I want a proper code to close my python script.
So far, I've used input('Press Any Key To Exit'), but what that does, is generate a error.
I would like a code that just closes your script without using a error.
Does anyone have a idea? Google gives me the input option, but I don't want that
It closes using this error:
Traceback (most recent call last):
File "C:/Python27/test", line 1, in <module>
input('Press Any Key To Exit')
File "<string>", line 0
^
SyntaxError: unexpected EOF while parsing
If you are on windows then the cmd pause command should work, although it reads 'press any key to continue'
import os
os.system('pause')
The linux alternative is read, a good description can be found here
This syntax error is caused by using input on Python 2, which will try to eval whatever is typed in at the terminal prompt. If you've pressed enter then Python will essentially try to eval an empty string, eval(""), which causes a SyntaxError instead of the usual NameError.
If you're happy for "any" key to be the enter key, then you can simply swap it out for raw_input instead:
raw_input("Press Enter to continue")
Note that on Python 3 raw_input was renamed to input.
For users finding this question in search, who really want to be able to press any key to exit a prompt and not be restricted to using enter, you may consider to use a 3rd-party library for a cross-platform solution. I recommend the helper library readchar which can be installed with pip install readchar. It works on Linux, macOS, and Windows and on either Python 2 or Python 3.
import readchar
print("Press Any Key To Exit")
k = readchar.readchar()
msvrct - built-in Python module solution (windows)
I would discourage platform specific functions in Python if you can avoid them, but you could use the built-in msvcrt module.
>>> from msvcrt import getch
>>>
>>>
... print("Press any key to continue...")
... _ = getch()
... exit()
A little late to the game, but I wrote a library a couple years ago to do exactly this. It exposes both a pause() function with a customizable message and the more general, cross-platform getch() function inspired by this answer.
Install with pip install py-getch, and use it like this:
from getch import pause
pause()
This prints 'Press any key to continue . . .' by default. Provide a custom message with:
pause('Press Any Key To Exit.')
For convenience, it also comes with a variant that calls sys.exit(status) in a single step:
pause_exit(0, 'Press Any Key To Exit.')
Check it out.
a = input('Press a key to exit')
if a:
exit(0)
Here's a way to end by pressing any key on *nix, without displaying the key and without pressing return. (Credit for the general method goes to Python read a single character from the user.) From poking around SO, it seems like you could use the msvcrt module to duplicate this functionality on Windows, but I don't have it installed anywhere to test. Over-commented to explain what's going on...
import sys, termios, tty
stdinFileDesc = sys.stdin.fileno() #store stdin's file descriptor
oldStdinTtyAttr = termios.tcgetattr(stdinFileDesc) #save stdin's tty attributes so I can reset it later
try:
print 'Press any key to exit...'
tty.setraw(stdinFileDesc) #set the input mode of stdin so that it gets added to char by char rather than line by line
sys.stdin.read(1) #read 1 byte from stdin (indicating that a key has been pressed)
finally:
termios.tcsetattr(stdinFileDesc, termios.TCSADRAIN, oldStdinTtyAttr) #reset stdin to its normal behavior
print 'Goodbye!'
Ok I am on Linux Mint 17.1 "Rebecca" and I seem to have figured it out, As you may know Linux Mint comes with Python installed, you cannot update it nor can you install another version on top of it. I've found out that the python that comes preinstalled in Linux Mint is version 2.7.6, so the following will for sure work on version 2.7.6. If you add raw_input('Press any key to exit') it will not display any error codes but it will tell you that the program exited with code 0. For example this is my first program. MyFirstProgram. Keep in mind it is my first program and I know that it sucks but it is a good example of how to use "Press any key to Exit"
BTW This is also my first post on this website so sorry if I formatted it wrong.
in Windows:
if msvcrt.kbhit():
if msvcrt.getch() == b'q':
exit()
In python 3:
while True:
#runtime..
answer = input("ENTER something to quit: ")
if answer:
break
You can use this code:
from os import system as console
console("#echo off&cls")
#Your main code code
print("Press Any Key To Exit")
console("pause>NUL&exit")

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