Develop Reference

Open random video file on a keypress

I am trying to write a program in Python that will open a random video file on a keypress(for me F8). I am very new to coding and currently stuck. I got it to the point where I am not getting any errors but now the program is not sticking around. Not sure what to do next. My code:
import os
import keyboard
import string
import random
from openfile import openfile
path = r"C:\Users\Rudy\Videos\GIFS"
letter = string.ascii_letters
digit = string.digits
def keyboardPress():
mp3Select = random.choice(os.listdir(path))
keypress = str(path + "\\" + mp3Select)
while True:
if keyboard.is_pressed('F8'):
openfile(keypress)
break
def main():
while True:
try:
keyboardPress()
except:
pass
main()

To open a random video on key press, you can use the event hooks in the keyboard module, one such event hook is keyboard.on_press(callback) which invokes a callback for every keydown event.
To prevent the program from terminating, you can use the method keyboard.wait(hotkey=None) which blocks the program execution until the given hotkey is pressed.
Use:
def keyPress(event):
if event.name == 'f8': # filter the `f8` key press event
fileName = random.choice(os.listdir(path))
filePath = os.path.join(path, fileName)
openfile(filePath) # open the video file
def main():
keyboard.on_press(keyPress) # hook up the event handler
keyboard.wait('esc') # blocks the program execution until `escape` key is pressed.
main()
Edit (see comments):
Use this while calling main():
try:
main()
except Exception as ex:
print(ex)

Python win32gui SetAsForegroundWindow function not working properly

I am trying to write a program that finds a window by searching for its title. Once it has found the window, it will attempt to bring it to front. I am using win32gui API to achieve this. I am able to get it to work for the most part, but for some reason it does not work if the taskmanager is in front. I have the follow sample code.
import win32gui, win32con
import re, traceback
from time import sleep
class cWindow:
def __init__(self):
self._hwnd = None
def BringToTop(self):
win32gui.BringWindowToTop(self._hwnd)
def SetAsForegroundWindow(self):
win32gui.SetForegroundWindow(self._hwnd)
def Maximize(self):
win32gui.ShowWindow(self._hwnd, win32con.SW_MAXIMIZE)
def setActWin(self):
win32gui.SetActiveWindow(self._hwnd)
def _window_enum_callback(self, hwnd, wildcard):
'''Pass to win32gui.EnumWindows() to check all the opened windows'''
if re.match(wildcard, str(win32gui.GetWindowText(hwnd))) != None:
self._hwnd = hwnd
def find_window_wildcard(self, wildcard):
self._hwnd = None
win32gui.EnumWindows(self._window_enum_callback, wildcard)
def main():
sleep(5)
try:
wildcard = ".*Building Operation WorkStation.*"
cW = cWindow()
cW.find_window_wildcard(wildcard)
cW.Maximize()
cW.BringToTop()
cW.SetAsForegroundWindow()
except:
f = open("log.txt", "w")
f.write(traceback.format_exc())
print traceback.format_exc()
main()
I pieced this together from multiple online sources. It seems to work for the most part but for some windows like the task manager, it'll work sometimes but fails the rest. When it doesnt work properly, all I notice is the application icon blinks yellow. Is there a proper way of doing this to make sure the window that I am interested in is set to foreground 100% of the times? I am not sure if this is relevant but I am using Windows 7 Professional (32-bit) with Service Pack 1.

I found a solution: if taskmanager, then kill it. I added a method to cWindow:
def kill_task_manager(self):
# Here I use your method to find a window because of an accent in my french OS,
# but you should use win32gui.FindWindow(None, 'Task Manager complete name').
wildcard = 'Gestionnaire des t.+ches de Windows'
self.find_window_wildcard(wildcard)
if self._hwnd:
win32gui.PostMessage(self._hwnd, win32con.WM_CLOSE, 0, 0) # kill it
sleep(0.5) # important to let time for the window to be closed
Call this method just after cW = cWindow().
Another bug trap is to prevent this exception in SetAsForegroundWindow:
error: (0, 'SetForegroundWindow', 'No error message is available')
just send an alt key before the win32gui call:
# Add this import
import win32com.client
# Add this to __ini__
self.shell = win32com.client.Dispatch("WScript.Shell")
# And SetAsForegroundWindow becomes
def SetAsForegroundWindow(self):
self.shell.SendKeys('%')
win32gui.SetForegroundWindow(self._hwnd)
Last, if I may, do not compare != None but is not None. More pythonic ;)
This is the full code:
# coding: utf-8
import re, traceback
import win32gui, win32con, win32com.client
from time import sleep
class cWindow:
def __init__(self):
self._hwnd = None
self.shell = win32com.client.Dispatch("WScript.Shell")
def BringToTop(self):
win32gui.BringWindowToTop(self._hwnd)
def SetAsForegroundWindow(self):
self.shell.SendKeys('%')
win32gui.SetForegroundWindow(self._hwnd)
def Maximize(self):
win32gui.ShowWindow(self._hwnd, win32con.SW_MAXIMIZE)
def setActWin(self):
win32gui.SetActiveWindow(self._hwnd)
def _window_enum_callback(self, hwnd, wildcard):
'''Pass to win32gui.EnumWindows() to check all the opened windows'''
if re.match(wildcard, str(win32gui.GetWindowText(hwnd))) is not None:
self._hwnd = hwnd
def find_window_wildcard(self, wildcard):
self._hwnd = None
win32gui.EnumWindows(self._window_enum_callback, wildcard)
def kill_task_manager(self):
wildcard = 'Gestionnaire des t.+ches de Windows'
self.find_window_wildcard(wildcard)
if self._hwnd:
win32gui.PostMessage(self._hwnd, win32con.WM_CLOSE, 0, 0)
sleep(0.5)
def main():
sleep(5)
try:
wildcard = ".*Building Operation WorkStation.*"
cW = cWindow()
cW.kill_task_manager()
cW.find_window_wildcard(wildcard)
cW.BringToTop()
cW.Maximize()
cW.SetAsForegroundWindow()
except:
f = open("log.txt", "w")
f.write(traceback.format_exc())
print(traceback.format_exc())
if __name__ == '__main__':
main()
Sources: how do I close window with handle using win32gui in Python and win32gui.SetActiveWindow() ERROR : The specified procedure could not be found.

Note: The following deals only with making sure that always-on-top windows such as Task Manager are hidden before activating the window - it assumes that the activation part itself works fine, which may not be the case. The conditions under which a process is allowed to call the SetForegroundWindow Windows API function are listed here.
Task Manager is special in two respects:
By default, it is set to display always on top, i.e., above all other windows.
Even when that is turned off (Options > Always on Top unchecked), you can still make it display on top of other always-on-top windows (something that ordinary windows seemingly cannot do).
Your code:
is working - in my tests - in the sense that the target window does become the active window.
is not working in the sense that the Task Manager window still stays on top of the (maximized) window.
even trying to make your window an always-on-top window as well wouldn't help, unfortunately.
Specifically checking for the presence of the Task Manager window and minimizing it is an option, but note that there may be other always-on-top windows, so for a robust solution you have to identify all open always-on-top windows and minimize them:
The following tries hard to identify all always-on-top windows except the Task Bar and Start button, and minimizes (effectively hides) any such windows.
The new methods are hide_always_on_top_windows and _window_enum_callback_hide.
import win32gui, win32con
import re, traceback
from time import sleep
class cWindow:
def __init__(self):
self._hwnd = None
def SetAsForegroundWindow(self):
# First, make sure all (other) always-on-top windows are hidden.
self.hide_always_on_top_windows()
win32gui.SetForegroundWindow(self._hwnd)
def Maximize(self):
win32gui.ShowWindow(self._hwnd, win32con.SW_MAXIMIZE)
def _window_enum_callback(self, hwnd, regex):
'''Pass to win32gui.EnumWindows() to check all open windows'''
if self._hwnd is None and re.match(regex, str(win32gui.GetWindowText(hwnd))) is not None:
self._hwnd = hwnd
def find_window_regex(self, regex):
self._hwnd = None
win32gui.EnumWindows(self._window_enum_callback, regex)
def hide_always_on_top_windows(self):
win32gui.EnumWindows(self._window_enum_callback_hide, None)
def _window_enum_callback_hide(self, hwnd, unused):
if hwnd != self._hwnd: # ignore self
# Is the window visible and marked as an always-on-top (topmost) window?
if win32gui.IsWindowVisible(hwnd) and win32gui.GetWindowLong(hwnd, win32con.GWL_EXSTYLE) & win32con.WS_EX_TOPMOST:
# Ignore windows of class 'Button' (the Start button overlay) and
# 'Shell_TrayWnd' (the Task Bar).
className = win32gui.GetClassName(hwnd)
if not (className == 'Button' or className == 'Shell_TrayWnd'):
# Force-minimize the window.
# Fortunately, this seems to work even with windows that
# have no Minimize button.
# Note that if we tried to hide the window with SW_HIDE,
# it would disappear from the Task Bar as well.
win32gui.ShowWindow(hwnd, win32con.SW_FORCEMINIMIZE)
def main():
sleep(5)
try:
regex = ".*Building Operation WorkStation.*"
cW = cWindow()
cW.find_window_regex(regex)
cW.Maximize()
cW.SetAsForegroundWindow()
except:
f = open("log.txt", "w")
f.write(traceback.format_exc())
print(traceback.format_exc())
main()

Retrieving intermediate values for raw_input [duplicate]

How can I poll the keyboard from a console python app? Specifically, I would like to do something akin to this in the midst of a lot of other I/O activities (socket selects, serial port access, etc.):
while True:
# doing amazing pythonic embedded stuff
# ...
# periodically do a non-blocking check to see if
# we are being told to do something else
x = keyboard.read(1000, timeout = 0)
if len(x):
# ok, some key got pressed
# do something
What is the correct pythonic way to do this on Windows? Also, portability to Linux wouldn't be bad, though it's not required.

The standard approach is to use the select module.
However, this doesn't work on Windows. For that, you can use the msvcrt module's keyboard polling.
Often, this is done with multiple threads -- one per device being "watched" plus the background processes that might need to be interrupted by the device.

A solution using the curses module. Printing a numeric value corresponding to each key pressed:
import curses
def main(stdscr):
# do not wait for input when calling getch
stdscr.nodelay(1)
while True:
# get keyboard input, returns -1 if none available
c = stdscr.getch()
if c != -1:
# print numeric value
stdscr.addstr(str(c) + ' ')
stdscr.refresh()
# return curser to start position
stdscr.move(0, 0)
if __name__ == '__main__':
curses.wrapper(main)

Ok, since my attempt to post my solution in a comment failed, here's what I was trying to say. I could do exactly what I wanted from native Python (on Windows, not anywhere else though) with the following code:
import msvcrt
def kbfunc():
x = msvcrt.kbhit()
if x:
ret = ord(msvcrt.getch())
else:
ret = 0
return ret

None of these answers worked well for me. This package, pynput, does exactly what I need.
https://pypi.python.org/pypi/pynput
from pynput.keyboard import Key, Listener
def on_press(key):
print('{0} pressed'.format(
key))
def on_release(key):
print('{0} release'.format(
key))
if key == Key.esc:
# Stop listener
return False
# Collect events until released
with Listener(
on_press=on_press,
on_release=on_release) as listener:
listener.join()

import sys
import select
def heardEnter():
i,o,e = select.select([sys.stdin],[],[],0.0001)
for s in i:
if s == sys.stdin:
input = sys.stdin.readline()
return True
return False

From the comments:
import msvcrt # built-in module
def kbfunc():
return ord(msvcrt.getch()) if msvcrt.kbhit() else 0
Thanks for the help. I ended up writing a C DLL called PyKeyboardAccess.dll and accessing the crt conio functions, exporting this routine:
#include <conio.h>
int kb_inkey () {
int rc;
int key;
key = _kbhit();
if (key == 0) {
rc = 0;
} else {
rc = _getch();
}
return rc;
}
And I access it in python using the ctypes module (built into python 2.5):
import ctypes
import time
# first, load the DLL
try:
kblib = ctypes.CDLL("PyKeyboardAccess.dll")
except:
raise ("Error Loading PyKeyboardAccess.dll")
# now, find our function
try:
kbfunc = kblib.kb_inkey
except:
raise ("Could not find the kb_inkey function in the dll!")
# Ok, now let's demo the capability
while True:
x = kbfunc()
if x != 0:
print "Got key: %d" % x
else:
time.sleep(.01)

I've come across a cross-platform implementation of kbhit at http://home.wlu.edu/~levys/software/kbhit.py (made edits to remove irrelevant code):
import os
if os.name == 'nt':
import msvcrt
else:
import sys, select
def kbhit():
''' Returns True if a keypress is waiting to be read in stdin, False otherwise.
'''
if os.name == 'nt':
return msvcrt.kbhit()
else:
dr,dw,de = select.select([sys.stdin], [], [], 0)
return dr != []
Make sure to read() the waiting character(s) -- the function will keep returning True until you do!

You might look at how pygame handles this to steal some ideas.

I am using this for checking for key presses, can't get much simpler:
#!/usr/bin/python3
# -*- coding: UTF-8 -*-
import curses, time
def main(stdscr):
"""checking for keypress"""
stdscr.nodelay(True) # do not wait for input when calling getch
return stdscr.getch()
while True:
print("key:", curses.wrapper(main)) # prints: 'key: 97' for 'a' pressed
# '-1' on no presses
time.sleep(1)
While curses is not working on windows, there is a 'unicurses' version, supposedly working on Linux, Windows, Mac but I could not get this to work

One more option would be to use sshkeyboard library to enable reacting to key presses instead of polling them periodically, and potentially missing the key press:
from sshkeyboard import listen_keyboard, stop_listening
def press(key):
print(f"'{key}' pressed")
if key == "z":
stop_listening()
listen_keyboard(on_press=press)
Simply pip install sshkeyboard to use it.

This can be done using 'pynput' module in python,
You press a key and it gets printed It's that easy!
PIP Install the module in command prompt, write following text and press enter
pip install pynput
Run the following code:
from pynput.keyboard import Key, Listener
def pressed(key):
print('Pressed:',key)
def released(key):
print('Released:',key)
if key == Key.enter:
# Stop detecting when enter key is pressed
return False
# Below loop for Detcting keys runs until enter key is pressed
with Listener(on_press=pressed, on_release=released) as detector:
detector.join()
You can end the loop with any key you want by changing Key.enter to some other key in the 8th line of the code.

If you combine time.sleep, threading.Thread, and sys.stdin.read you can easily wait for a specified amount of time for input and then continue,
also this should be cross-platform compatible.
t = threading.Thread(target=sys.stdin.read(1) args=(1,))
t.start()
time.sleep(5)
t.join()
You could also place this into a function like so
def timed_getch(self, bytes=1, timeout=1):
t = threading.Thread(target=sys.stdin.read, args=(bytes,))
t.start()
time.sleep(timeout)
t.join()
del t
Although this will not return anything so instead you should use the multiprocessing pool module you can find that here: how to get the return value from a thread in python?

Can I use Python's curses and cmd libraries together?

In Python, I'd like to write a terminal program using both cmd and curses together, ie. use cmd to accept and decode full input lines, but position the output with curses.
Mashing together examples of both curses and cmd like this :
import curses
import cmd
class HelloWorld(cmd.Cmd):
"""Simple command processor example."""
def do_greet(self, line):
screen.clear()
screen.addstr(1,1,"hello "+line)
screen.addstr(0,1,">")
screen.refresh()
def do_q(self, line):
curses.endwin()
return True
if __name__ == '__main__':
screen = curses.initscr()
HelloWorld().cmdloop()
I find that I'm not seeing anything when I type. curses is presumably waiting for a refresh before displaying anything on the screen. I could switch to using getch() but then I'd lose the value of cmd.
Is there a way to make these work together?

The question seems to be very old... But it attracted enough of attention so i thought to leave my answer behind.. You can check out the site here and clear your doubts..
Update : this answer links to the gist from the original questioner. Just to save someone having to follow the link ... here's the code in full :
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import curses
import curses.textpad
import cmd
def maketextbox(h,w,y,x,value="",deco=None,textColorpair=0,decoColorpair=0):
# thanks to http://stackoverflow.com/a/5326195/8482 for this
nw = curses.newwin(h,w,y,x)
txtbox = curses.textpad.Textbox(nw,insert_mode=True)
if deco=="frame":
screen.attron(decoColorpair)
curses.textpad.rectangle(screen,y-1,x-1,y+h,x+w)
screen.attroff(decoColorpair)
elif deco=="underline":
screen.hline(y+1,x,underlineChr,w,decoColorpair)
nw.addstr(0,0,value,textColorpair)
nw.attron(textColorpair)
screen.refresh()
return nw,txtbox
class Commands(cmd.Cmd):
"""Simple command processor example."""
def __init__(self):
cmd.Cmd.__init__(self)
self.prompt = "> "
self.intro = "Welcome to console!" ## defaults to None
def do_greet(self, line):
self.write("hello "+line)
def default(self,line) :
self.write("Don't understand '" + line + "'")
def do_quit(self, line):
curses.endwin()
return True
def write(self,text) :
screen.clear()
textwin.clear()
screen.addstr(3,0,text)
screen.refresh()
if __name__ == '__main__':
screen = curses.initscr()
curses.noecho()
textwin,textbox = maketextbox(1,40, 1,1,"")
flag = False
while not flag :
text = textbox.edit()
curses.beep()
flag = Commands().onecmd(text)

disable or lock mouse and keyboard in Python?

Is there a way of disabling or locking mouse and keyboard using python? I want to freeze the mouse and disable the keyboard.

I haven't tested (actually I've tested the mouse part, and it annoyingly works) but something like this using pyhook would do what you want:
import pythoncom, pyHook
def uMad(event):
return False
hm = pyHook.HookManager()
hm.MouseAll = uMad
hm.KeyAll = uMad
hm.HookMouse()
hm.HookKeyboard()
pythoncom.PumpMessages()

I have extended Fábio Diniz's answer to a class which provides both a block() and an unblock() function which block (selectively) mouse/keyboard inputs. I also added a timeout functionality which (hopefully) addresses the annoyance of locking oneself out.
import pyHook
from threading import Timer
import win32gui
import logging
class blockInput():
def OnKeyboardEvent(self,event):
return False
def OnMouseEvent(self,event):
return False
def unblock(self):
logging.info(" -- Unblock!")
if self.t.is_alive():
self.t.cancel()
try: self.hm.UnhookKeyboard()
except: pass
try: self.hm.UnhookMouse()
except: pass
def block(self, timeout = 10, keyboard = True, mouse = True):
self.t = Timer(timeout, self.unblock)
self.t.start()
logging.info(" -- Block!")
if mouse:
self.hm.MouseAll = self.OnMouseEvent
self.hm.HookMouse()
if keyboard:
self.hm.KeyAll = self.OnKeyboardEvent
self.hm.HookKeyboard()
win32gui.PumpWaitingMessages()
def __init__(self):
self.hm = pyHook.HookManager()
if __name__ == '__main__':
logging.basicConfig(level=logging.INFO)
block = blockInput()
block.block()
import time
t0 = time.time()
while time.time() - t0 < 10:
time.sleep(1)
print(time.time() - t0)
block.unblock()
logging.info("Done.")
You can have a look at the main routine for example usage.

For me, just two lines of programming solved the problem:
from ctypes import *
ok = windll.user32.BlockInput(True) #enable block
#or
ok = windll.user32.BlockInput(False) #disable block

Totally different take since all the solutions mentioned above use a quiet outdated library(pyhook) and this pyhook method personally didnt work for me.
import keyboard
from pynput.mouse import Controller
from time import sleep
def blockinput():
global block_input_flag
block_input_flag = 1
t1 = threading.Thread(target=blockinput_start)
t1.start()
print("[SUCCESS] Input blocked!")
def unblockinput():
blockinput_stop()
print("[SUCCESS] Input unblocked!")
def blockinput_start():
mouse = Controller()
global block_input_flag
for i in range(150):
keyboard.block_key(i)
while block_input_flag == 1:
mouse.position = (0, 0)
def blockinput_stop():
global block_input_flag
for i in range(150):
keyboard.unblock_key(i)
block_input_flag = 0
blockinput()
print("now blocking")
sleep(5)
print("now unblocking")

I just slightly modified the #Robert code and instead of the time I used external interrupt to close the program i.e. if you connect any external drive then the program gets close and your mouse and keyboard will be working perfectly.
import pyHook
from threading import Timer
import win32gui
import logging
import win32file
def locate_usb():#this will check any external Drives
drive_list = []
drivebits = win32file.GetLogicalDrives()
# print(drivebits)
for d in range(1, 26):
mask = 1 << d
if drivebits & mask:
# here if the drive is at least there
drname = '%c:\\' % chr(ord('A') + d)
t = win32file.GetDriveType(drname)
if t == win32file.DRIVE_REMOVABLE:
drive_list.append(drname)
return drive_list
class blockInput():
def OnKeyboardEvent(self,event):
return False
def OnMouseEvent(self,event):
return False
def unblock(self):
try: self.hm.UnhookKeyboard()
except: pass
try: self.hm.UnhookMouse()
except: pass
def block(self ,keyboard = True, mouse = True):
while(1):
if mouse:
self.hm.MouseAll = self.OnMouseEvent
self.hm.HookMouse()
if keyboard:
self.hm.KeyAll = self.OnKeyboardEvent
self.hm.HookKeyboard()
win32gui.PumpWaitingMessages()
cg= locate_usb()
if cg:
break
def __init__(self):
self.hm = pyHook.HookManager()
if __name__ == '__main__':
block = blockInput()
block.block()
block.unblock()
I hope this code will help you

Since 2018, you can now use pynput (v1.4+) to suppress keyboard and mouse events on Windows, Mac, and Linux.
import pynput
# Disable mouse and keyboard events
mouse_listener = pynput.mouse.Listener(suppress=True)
mouse_listener.start()
keyboard_listener = pynput.keyboard.Listener(suppress=True)
keyboard_listener.start()
# Enable mouse and keyboard events
mouse_listener.stop()
keyboard_listener.stop()
This also disables mouse scrolling and clicking.
However, this does not stop users from pressing Ctrl+Alt+Del on Windows. But you can run the script in an elevated command prompt, and the mouse and keyboard will still be disabled, even if they opened Task Manager using Ctrl+Alt+Delete, so there is no harm done (apparently there are way to actually prevent Ctrl+Alt+Delete, but do your own research for that)

You can use pyautogui to do this. Though I recommend adding keyboard for making a stopping key. First, you want to install pyautogui and keyboard.
Please note: this only disables the mouse not the keyboard, that is a very bad idea.
pip install pyautogui
pip install keyboard
Ok, with that sorted, we have to actually make the disabler.
import pyautogui
import keyboard
stopKey = "s" #The stopKey is the button to press to stop. you can also do a shortcut like ctrl+s
maxX, maxY = pyautogui.size() #get max size of screen
While True:
if keyboard.is_pressed(stopKey):
break
else:
pyautogui.moveTo(maxX/2, maxY/2) #move the mouse to the center of the screen
Ok, but there is 2 ways to get out of this. pressing S, and also quickly moving the mouse to one of the corners of the screen (that is a pyautogui failsafe, but we can disable that). If you want to disable the failsafe, add this after the imports:
pyautogui.FAILSAFE = False
Please note that disabling the failsafe is NOT recommended!
Ok, so now the only way to exit is the S key. If you want to stop this somewhere else in your program, do this:
pyautogui.press(stopKey)
Ok, so its not perfect, but it will stop you from doing basically anything with your mouse.