Python module to page output to the screen, read keys and get console dimensions.

It was meant to be included in standard library http://bugs.python.org/issue8408

Author: anatoly techtonik <techtonik@gmail.com>
License: Public Domain (or MIT if a license is required)

Demo

python -m pager <file>

# run manual tests that are also a demo
python -m pager --test

Status

3.0 (stable) - API break in getch() function

• reverted getch() behaviour changed in 2.0 - now getch() again returns single char
• new getchars() function that always returns list

2.1 (stable)

• split getch() into _getch_unix() and _getch_windows() and detect correct flavor at import time (speedup)

2.0 (stable) - API break in getch() function

• getch() now always returns list of characters (previously it could return single char). This is done to simplify the task of detecting keys from the returned result

1.4 (stable)

• pager.py <file>
• Linux: termios comments, docs and preparation for very likely API break in getch() function

1.3 (stable)

• Windows: Python 3 requires getwch()
• Windows: fix ENTER LEFT UP RIGHT DOWN ESC key codes

1.2 (stable)

• add names for ENTER LEFT UP RIGHT DOWN ESC keys
• manual tests for getch() (fixes bug #4)
• dumpkey() helper function to get hex dump of a value returned by getch()

1.1 (stable)

• Python 3 compatibility
• echo() helper function for unbuffered output (in Py3 output doesn't appear immediately on screen unless it ends with newline)

1.0 (stable)

• getch() now returns list of chars for special keys (fixes bug #1 when special key skipped several pages)
• page() callbacks receive obligatory pagenumber param
• default page() callback now shows page number

0.2 (stable)

• do not insert blank line between pages

0.1 (stable)

• shows content page by page
• allows to get console/terminal dimensions
• works on Windows
• works on Linux

API (output)

..function:: page(content, [pagecallback=prompt])

Output content iterable, calling pagecallback function after each page with page number as a parameter. Default prompt() callback shows page number with 'Press any key . . . ' prompt and waits for keypress.

..function:: echo(msg)

Print msg to the screen without linefeed and flush the output.

..function:: getwidth()

Return width of available window in characters. If detection fails, return value of standard width 80. Coordinate of the last character on a line is -1 from returned value.

..function:: getheight()

Return available window height in characters or 25 if detection fails. Coordinate of the last line is -1 from returned value.

API (input)

..function:: getch()

Wait for keypress, return first char generated as a result.

Arrows and special keys generate sequence of chars. Use getchars function to receive all chars generated or present in buffer.

..function:: getchars()

Wait for keypress. Return list of chars generated as a result. More than one char in result list is returned when arrows and special keys are pressed. Returned sequences differ between platforms, so use constants defined in this module to guess correct keys.

..function:: dumpkey(key)

Helper to convert result of getch (string) or getchars (list) to hex string.

Credits

Danny Yoo for getch()-like unbuffered character reading recipe http://code.activestate.com/recipes/134892-getch-like-unbuffered/

References

Excellent tutorials for Win32 Console by Adrian Worley http://www.adrianxw.dk/SoftwareSite/index.html Console Reference on MSDN http://msdn.microsoft.com/en-us/library/ms682087%28VS.85%29.aspx

Public Domain Curses library maintained by William McBrine http://pdcurses.sourceforge.net/

Ioctl (input/output control) introduction from Wikipedia http://en.wikipedia.org/wiki/Ioctl Linux Programmer's Manual - ioctls for terminals and serial lines http://www.kernel.org/doc/man-pages/online/pages/man4/tty_ioctl.4.html