How to make a script wait for a pressed key?
In Python 3 use input()
:
input("Press Enter to continue...")
In Python 2 use raw_input()
:
raw_input("Press Enter to continue...")
This only waits for the user to press enter though.
One might want to use msvcrt ((Windows/DOS only) The msvcrt module gives you access to a number of functions in the Microsoft Visual C/C++ Runtime Library (MSVCRT)):
import msvcrt as m
def wait():
m.getch()
This should wait for a key press.
Additional info:
in Python 3 raw_input()
does not exist
In Python 2 input(prompt)
is equivalent to eval(raw_input(prompt))
One way to do this in Python 2, is to use raw_input()
:
raw_input("Press Enter to continue...")
In python3 it's just input()
On my linux box, I use the following code. This is similar to code I've seen elsewhere (in the old python FAQs for instance) but that code spins in a tight loop where this code doesn't and there are lots of odd corner cases that code doesn't account for that this code does.
def read_single_keypress():
"""Waits for a single keypress on stdin.
This is a silly function to call if you need to do it a lot because it has
to store stdin's current setup, setup stdin for reading single keystrokes
then read the single keystroke then revert stdin back after reading the
keystroke.
Returns a tuple of characters of the key that was pressed - on Linux,
pressing keys like up arrow results in a sequence of characters. Returns
('\x03',) on KeyboardInterrupt which can happen when a signal gets
handled.
"""
import termios, fcntl, sys, os
fd = sys.stdin.fileno()
# save old state
flags_save = fcntl.fcntl(fd, fcntl.F_GETFL)
attrs_save = termios.tcgetattr(fd)
# make raw - the way to do this comes from the termios(3) man page.
attrs = list(attrs_save) # copy the stored version to update
# iflag
attrs[0] &= ~(termios.IGNBRK | termios.BRKINT | termios.PARMRK
| termios.ISTRIP | termios.INLCR | termios. IGNCR
| termios.ICRNL | termios.IXON )
# oflag
attrs[1] &= ~termios.OPOST
# cflag
attrs[2] &= ~(termios.CSIZE | termios. PARENB)
attrs[2] |= termios.CS8
# lflag
attrs[3] &= ~(termios.ECHONL | termios.ECHO | termios.ICANON
| termios.ISIG | termios.IEXTEN)
termios.tcsetattr(fd, termios.TCSANOW, attrs)
# turn off non-blocking
fcntl.fcntl(fd, fcntl.F_SETFL, flags_save & ~os.O_NONBLOCK)
# read a single keystroke
ret = []
try:
ret.append(sys.stdin.read(1)) # returns a single character
fcntl.fcntl(fd, fcntl.F_SETFL, flags_save | os.O_NONBLOCK)
c = sys.stdin.read(1) # returns a single character
while len(c) > 0:
ret.append(c)
c = sys.stdin.read(1)
except KeyboardInterrupt:
ret.append('\x03')
finally:
# restore old state
termios.tcsetattr(fd, termios.TCSAFLUSH, attrs_save)
fcntl.fcntl(fd, fcntl.F_SETFL, flags_save)
return tuple(ret)