terminal_utils - Helper functions for input from/output to a terminal
5.6.11. terminal_utils - Helper functions for input from/output to a terminal#
This module contains modules useful to deal with output on the terminal:
Pager
, a class to provide paginated output with less similar to other popular tools likegit diff
InputEditor
, a class to open an editor window when requesting longer inputs from users, similar togit commit
- class terminal_utils.ANSIColors(value)[source]#
Simple class to handle color output to the terminal.
This class allows to very easily add color output to the terminal
>>> from terminal_utils import ANSIColors as ac >>> print(f"{ac.fg('red')}Some text in {ac.color(underline=True)}RED{ac.reset()}")
The basic colors can be specified by name (case insensitive) or by enum value. Custom colors can be supplied using hex notation like
#rgb
or#rrggbb
(Hint:matplotlib.colors.to_hex
might be useful here). As an example to use the viridis colormap to color the output on the terminal:from matplotlib import cm from matplotlib.colors import to_hex from terminal_utils import ANSIColors as ac # sample the viridis colormap at 16 points for i in range(16): # convert i to be in [0..1] and get the hex color color = to_hex(cm.viridis(i/15)) # and print the hex color in the correct color print(f"{i}. {ac.fg(color)}{color}{ac.reset()}")
If the output is not to a terminal color output will be disabled and nothing will be added to the output, for example when redirecting the output to a logfile.
- classmethod bg(color)[source]#
Shorthand for
color(background=color)
- classmethod color(foreground=None, background=None, bold=False, underline=False, inverted=False)[source]#
Change terminal colors to the given foreground/background colors and attributes.
This will return a string to be printed to change the color on the terminal. To revert to default print the output of
reset()
- Parameters
foreground (int or str) – foreground color to use, can be any value accepted by
convert_color
If None is given the current color will not be changed.background (int or str) – background color to use, can be any value accepted by
convert_color
. If None is given the current color will not be changed.bold (bool) – Use bold font
underline (bool) – Underline the text
inverted (bool) – Flip background and foreground color
- classmethod convert_color(color)[source]#
Convert a color to the necessary ansi code. The argument can either bei
an integer corresponding to the ansi color (see the enum values of this class)
the name (case insensitive) of one of the enum values of this class
a hex color code of the form
#rgb
or#rrggbb
- Raises
KeyError – if the argument is a string not matching to one of the known colors
- classmethod fg(color)[source]#
Shorthand for
color(foreground=color)
- class terminal_utils.InputEditor(editor_command: Optional[str] = None, initial_content: Optional[str] = None, commentlines_start_with: str = '#')[source]#
Class to get user input via opening a temporary file in a text editor.
It is an alternative to the python commands
input()
orsys.stdin.readlines
and is similar to the behaviour ofgit commit
for editing commit messages. By using an editor instead of the command line, the user is motivated to give expressive multi-line input, leveraging the full text editing capabilities of his editor. This function cannot be used for example in interactive terminal scripts, whenever detailed user input is required.Heavily inspired by the code in this blog post: https://chase-seibert.github.io/blog/2012/10/31/python-fork-exec-vim-raw-input.html
- Parameters
editor_command – Editor to open for user input. If
None
, get default editor from environment variables. It should be the name of a shell executable and can contain command line arguments.initial_content – Initial string to insert into the temporary file that is opened for user input. Can be used for default input or to insert comment lines with instructions.
commentlines_start_with – Optionally define string with which comment lines start
- comment_string#
string which starts comments in the file
- editor_command_list#
command line for the editor, split to seperate executable name command line arguments
- initial_content#
initial content of the editor window
- class terminal_utils.Pager(prompt=None, quit_if_one_screen=False)[source]#
Context manager providing page-wise output using
less
, similar to how git handles long output of for examplegit diff
. Paging will only be active if the output is to a terminal and not piped into a file or to a different program.Warning
To be able to see
basf2
log messages likeB2INFO()
on the paged output you have to setbasf2.logging.enable_python_logging = True
Changed in version release-03-00-00: the pager no longer waits until all output is complete but can incrementally show output. It can also show output generated in C++
You can set the environment variable
$PAGER
to an empty string or tocat
to disable paging or to a different program (for examplemore
) which should retrieve the output and display it.- Parameters
prompt (str) – a string argument allows overriding the description provided by
less
. Special characters may need escaping. Will only be shown if paging is used and the pager is actuallyless
.quit_if_one_screen (bool) – indicating whether the Pager should quit automatically if the content fits on one screen. This implies that the content stays visible on pager exit. True is similar to the behavior of git diff, False is similar to git --help