"""
This module defines simple functions to color your text and highlight your code
using `ANSI <https://en.wikipedia.org/wiki/ANSI_escape_code#Colors>`_ escape
sequences. This works using the `Pygments <http://pygments.org/>`_ library,
which is an optional requirement. Therefore, these functions only work properly
if Pygments is installed, otherwise these functions will return the unmodified
text and a warning will be printed.
The :func:`highlight_code` function uses pygments to highlight syntax of a
programming language.
The :func:`color_text` function colors text with a solid color.
Note the functions in this module require the optional :mod:`pygments`
library to work correctly. These functions will warn if :mod:`pygments` is
not installed.
This module contains a global variable ``NO_COLOR``, which if set to True will
force all ANSI text coloring functions to become no-ops. This defaults to the
value of the ``bool(os.environ.get('NO_COLOR'))`` flag, which is compliant with
[NoColor]_.
Related work:
https://github.com/Textualize/rich
References:
.. [NoColor] https://no-color.org/
Requirements:
pip install pygments
"""
import sys
import warnings
import os
# Global state that determines if ANSI-coloring text is allowed
# (which is mainly to address non-ANSI compliant windows consoles)
# compliant with https://no-color.org/
NO_COLOR = bool(os.environ.get('NO_COLOR')) # type: bool
[docs]def highlight_code(text, lexer_name='python', **kwargs):
"""
Highlights a block of text using ANSI tags based on language syntax.
Args:
text (str): plain text to highlight
lexer_name (str): name of language. eg: python, docker, c++
**kwargs: passed to pygments.lexers.get_lexer_by_name
Returns:
str:
text - highlighted text If pygments is not installed, the plain
text is returned.
Example:
>>> import ubelt as ub
>>> text = 'import ubelt as ub; print(ub)'
>>> new_text = ub.highlight_code(text)
>>> print(new_text)
"""
if NO_COLOR:
return text
# Resolve extensions to languages
lexer_name = {
'py': 'python',
'h': 'cpp',
'cpp': 'cpp',
'cxx': 'cpp',
'c': 'cpp',
}.get(lexer_name.replace('.', ''), lexer_name)
try:
if sys.platform.startswith('win32'): # nocover
# Hack on win32 to support colored output
try:
import colorama
if not colorama.initialise.atexit_done:
# Only init if it hasn't been done
colorama.init()
except ImportError:
warnings.warn(
'colorama is not installed, ansi colors may not work')
import pygments # type: ignore
import pygments.lexers # type: ignore
import pygments.formatters # type: ignore
import pygments.formatters.terminal # type: ignore
formatter = pygments.formatters.terminal.TerminalFormatter(bg='dark')
lexer = pygments.lexers.get_lexer_by_name(lexer_name, **kwargs)
new_text = pygments.highlight(text, lexer, formatter)
except ImportError: # nocover
warnings.warn('pygments is not installed, code will not be highlighted')
new_text = text
return new_text
[docs]def color_text(text, color):
r"""
Colorizes text a single color using ansi tags.
Args:
text (str): text to colorize
color (str): color code. different systems may have different colors.
commonly available colors are: 'red', 'brown', 'yellow', 'green',
'blue', 'black', and 'white'.
Returns:
str:
text - colorized text. If pygments is not installed plain text is
returned.
Example:
>>> text = 'raw text'
>>> import pytest
>>> import ubelt as ub
>>> if ub.modname_to_modpath('pygments'):
>>> # Colors text only if pygments is installed
>>> ansi_text = ub.color_text(text, 'red')
>>> prefix = '\x1b[31'
>>> print('prefix = {!r}'.format(prefix))
>>> print('ansi_text = {!r}'.format(ansi_text))
>>> assert ansi_text.startswith(prefix)
>>> assert ub.color_text(text, None) == 'raw text'
>>> else:
>>> # Otherwise text passes through unchanged
>>> assert ub.color_text(text, 'red') == 'raw text'
>>> assert ub.color_text(text, None) == 'raw text'
Example:
>>> # xdoctest: +REQUIRES(module:pygments)
>>> import pygments.console
>>> import ubelt as ub
>>> known_colors = pygments.console.codes.keys()
>>> for color in known_colors:
... print(ub.color_text(color, color))
"""
if NO_COLOR or color is None:
return text
try:
if sys.platform.startswith('win32'): # nocover
# Hack on win32 to support colored output
try:
import colorama
if not colorama.initialise.atexit_done:
# Only init if it hasn't been done
colorama.init()
except ImportError:
warnings.warn(
'colorama is not installed, ansi colors may not work')
import pygments # type: ignore
import pygments.console # type: ignore
try:
ansi_text = pygments.console.colorize(color, text)
except KeyError:
warnings.warn('unable to find color: {!r}'.format(color))
return text
except Exception as ex: # nocover
warnings.warn('some other issue with text color: {!r}'.format(ex))
return text
return ansi_text
except ImportError: # nocover
warnings.warn('pygments is not installed, text will not be colored')
return text