Stem Docs

stem.util.term

Source code for stem.util.term

# Copyright 2011-2013, Damian Johnson and The Tor Project
# See LICENSE for licensing information

"""
Utilities for working with the terminal.

**Module Overview:**

::

  format - wrap text with ANSI for the given colors or attributes

.. data:: Color (enum)
.. data:: BgColor (enum)

  Enumerations for foreground or background terminal color.

  =========== ===========
  Color       Description
  =========== ===========
  **BLACK**   black color
  **BLUE**    blue color
  **CYAN**    cyan color
  **GREEN**   green color
  **MAGENTA** magenta color
  **RED**     red color
  **WHITE**   white color
  **YELLOW**  yellow color
  =========== ===========

.. data:: Attr (enum)

  Enumerations of terminal text attributes.

  ============= ===========
  Attr          Description
  ============= ===========
  **BOLD**      heavy typeface
  **HILIGHT**   inverted foreground and background
  **UNDERLINE** underlined text
  ============= ===========
"""

import stem.util.enum
import stem.util.str_tools

TERM_COLORS = ("BLACK", "RED", "GREEN", "YELLOW", "BLUE", "MAGENTA", "CYAN", "WHITE")

Color = stem.util.enum.Enum(*TERM_COLORS)
BgColor = stem.util.enum.Enum(*["BG_" + color for color in TERM_COLORS])
Attr = stem.util.enum.Enum("BOLD", "UNDERLINE", "HILIGHT")

# mappings of terminal attribute enums to their ANSI escape encoding
FG_ENCODING = dict([(list(Color)[i], str(30 + i)) for i in range(8)])
BG_ENCODING = dict([(list(BgColor)[i], str(40 + i)) for i in range(8)])
ATTR_ENCODING = {Attr.BOLD: "1", Attr.UNDERLINE: "4", Attr.HILIGHT: "7"}

CSI = "\x1B[%sm"
RESET = CSI % "0"


[docs]def format(msg, *attr): """ Simple terminal text formatting using `ANSI escape sequences <https://secure.wikimedia.org/wikipedia/en/wiki/ANSI_escape_code#CSI_codes>`_. The following are some toolkits providing similar capabilities: * `django.utils.termcolors <https://code.djangoproject.com/browser/django/trunk/django/utils/termcolors.py>`_ * `termcolor <http://pypi.python.org/pypi/termcolor>`_ * `colorama <http://pypi.python.org/pypi/colorama>`_ :param str msg: string to be formatted :param str attr: text attributes, this can be :data:`~stem.util.term.Color`, :data:`~stem.util.term.BgColor`, or :data:`~stem.util.term.Attr` enums and are case insensitive (so strings like "red" are fine) :returns: **str** wrapped with ANSI escape encodings, starting with the given attributes and ending with a reset """ # if we have reset sequences in the message then apply our attributes # after each of them if RESET in msg: return "".join([format(comp, *attr) for comp in msg.split(RESET)]) encodings = [] for text_attr in attr: text_attr, encoding = stem.util.str_tools._to_camel_case(text_attr), None encoding = FG_ENCODING.get(text_attr, encoding) encoding = BG_ENCODING.get(text_attr, encoding) encoding = ATTR_ENCODING.get(text_attr, encoding) if encoding: encodings.append(encoding) if encodings: return (CSI % ";".join(encodings)) + msg + RESET else: return msg