raw_input in python without pressing enter

问题

I\'m using raw_input in Python to interact with user in shell.

c = raw_input(\'Press s or n to continue:\')
if c.upper() == \'S\':
    print \'YES\'

It works as intended, but the user has to press enter in the shell after pressing \'s\'. Is there a way to accomplish what I need from an user input without needing to press enter in the shell? I\'m using *nixes machines.

回答1:

Under Windows, you need the msvcrt module, specifically, it seems from the way you describe your problem, the function msvcrt.getch:

Read a keypress and return the resulting character. Nothing is echoed to the console. This call will block if a keypress is not already available, but will not wait for Enter to be pressed.

(etc -- see the docs I just pointed to). For Unix, see e.g. this recipe for a simple way to build a similar getch function (see also several alternatives &c in the comment thread of that recipe).

回答2:

Python does not provide a multiplatform solution out of the box.
If you are on Windows you could try msvcrt with:

import msvcrt
print 'Press s or n to continue:\n'
input_char = msvcrt.getch()
if input_char.upper() == 'S': 
   print 'YES'

回答3:

curses can do that as well :

import curses, time

#--------------------------------------
def input_char(message):
    try:
        win = curses.initscr()
        win.addstr(0, 0, message)
        while True: 
            ch = win.getch()
            if ch in range(32, 127): break
            time.sleep(0.05)
    except: raise
    finally:
        curses.endwin()
    return chr(ch)
#--------------------------------------
c = input_char('Press s or n to continue:')
if c.upper() == 'S':
    print 'YES'

回答4:

Instead of the msvcrt module you could also use WConio:

>>> import WConio
>>> ans = WConio.getkey()
>>> ans
'y'

回答5:

To get a single character, I have used getch, but I don't know if it works on Windows.

回答6:

On a side note, msvcrt.kbhit() returns a boolean value determining if any key on the keyboard is currently being pressed.

So if you're making a game or something and want keypresses to do things but not halt the game entirely, you can use kbhit() inside an if statement to make sure that the key is only retrieved if the user actually wants to do something.

An example in Python 3:

# this would be in some kind of check_input function
if msvcrt.kbhit():
    key = msvcrt.getch().decode("utf-8").lower() # getch() returns bytes data that we need to decode in order to read properly. i also forced lowercase which is optional but recommended
    if key == "w": # here 'w' is used as an example
        # do stuff
    elif key == "a":
        # do other stuff
    elif key == "j":
        # you get the point

回答7:

I know this is old, but the solution wasn't good enough for me. I need the solution to support cross-platform and without installing any external Python packages.

My solution for this, in case anyone else comes across this post

Reference: https://github.com/unfor19/mg-tools/blob/master/mgtools/get_key_pressed.py

from tkinter import Tk, Frame


def __set_key(e, root):
    """
    e - event with attribute 'char', the released key
    """
    global key_pressed
    if e.char:
        key_pressed = e.char
        root.destroy()


def get_key(msg="Press any key ...", time_to_sleep=3):
    """
    msg - set to empty string if you don't want to print anything
    time_to_sleep - default 3 seconds
    """
    global key_pressed
    if msg:
        print(msg)
    key_pressed = None
    root = Tk()
    root.overrideredirect(True)
    frame = Frame(root, width=0, height=0)
    frame.bind("<KeyRelease>", lambda f: __set_key(f, root))
    frame.pack()
    root.focus_set()
    frame.focus_set()
    frame.focus_force()  # doesn't work in a while loop without it
    root.after(time_to_sleep * 1000, func=root.destroy)
    root.mainloop()
    root = None  # just in case
    return key_pressed


def __main():
        c = None
        while not c:
                c = get_key("Choose your weapon ... ", 2)
        print(c)

if __name__ == "__main__":
    __main()

来源：https://stackoverflow.com/questions/3523174/raw-input-in-python-without-pressing-enter

标签

python

user-input