How to Read a Single Character from User Input Across Different Platforms?

Reading a Single Character from User Input Cross-Platform

In various programming scenarios, it becomes necessary to read a single character from user input without buffering or echoing. This functionality is similar to the renowned getch() function available in Windows, but a universal approach that works across multiple platforms is desired.

Solution:

To achieve this cross-platform character reading, you can utilize a community-driven Python recipe from the ActiveState Recipes site: "getch()-like unbuffered character reading from stdin on both Windows and Unix." This recipe provides a class-based implementation, catering to both Windows and Unix-based systems.

Implementation:

The following code snippet demonstrates the implementation of the cross-platform character reading class:

class _Getch:
    """Gets a single character from standard input.  Does not echo to the
screen."""
    def __init__(self):
        try:
            self.impl = _GetchWindows()
        except ImportError:
            self.impl = _GetchUnix()

    def __call__(self):
        return self.impl()


class _GetchUnix:
    def __init__(self):
        import tty, sys

    def __call__(self):
        import sys, tty, termios
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch


class _GetchWindows:
    def __init__(self):
        import msvcrt

    def __call__(self):
        import msvcrt
        return msvcrt.getch()


getch = _Getch()

To utilize this class, simply instantiate the _Getch class and call it. The result will be the single character typed by the user, without any buffering or echoing. For instance:

result = getch()

Conclusion:

This cross-platform character reading approach is widely applicable in situations where immediate user input is required, such as capturing keystrokes in terminal applications or implementing interactive user interfaces.

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