A $PAGER in pure Python
pip install pypager
Pypager can be used as a stand-alone application, or as a library.
What is a pager?
A pager is a terminal program that can be used to view the content of a file, or the output stream from another application.
For instance, when we run
man vim, the actual content is displayed in a
pager, according to the
$PAGER environment variable.
Important for a pager is that the input can be streamed. For instance when we
find / | pypager; we don't want to wait for the whole file system
to be traversed, before displaying anything. Data is only read from the input
pipe, when it needs to be displayed.
Popular pager applications are
- Highlighting of text .
- Many key bindings from
 (It understands the output of man pages, ANSI escape codes and further, it can use Pygments to highlight about any file.)
# Install it. pip install pypager # Tell the environment to use this pager. Put the following line in # ~/.bashrc if you like. export PAGER=pypager # Following commands, and many others should pick up the pager. man vim git diff # View a file, using this pager. pypager some_source_code.py
As a library
from pypager.source import GeneratorSource from pypager.pager import Pager from prompt_toolkit.token import Token def generate_a_lot_of_content(): """ This is a function that generates content on the fly. It's called when the pager needs to display more content. """ counter = 0 while True: yield [(Token, 'line: %i\n' % counter)] counter += 1 if __name__ == '__main__': source = GeneratorSource(generate_a_lot_of_content()) p = Pager(source) p.run()