Controlling colour¶

Simple colours its output with ANSI escape codes. gouge follows the NO_COLOR convention and the FORCE_COLOR variable used by many tools, and strips colour when the output is not a terminal.

Precedence¶

The decision is taken when the formatter is created, in this order. The first rule that applies wins:

An environment variable counts as set when it is not empty. FORCE_COLOR wins over NO_COLOR.

basicConfig() lets colorama remove the codes when the stream is not a terminal, for example when the output is piped into a file. A formatter created directly cannot know where its output goes and emits colour codes unless NO_COLOR is set.

Switch colour off¶

Set NO_COLOR in the environment. The output then holds no escape codes at all, including those added by pre-formatters:

>>> import logging
>>> import os
>>> from gouge.colourcli import Simple
>>> record = logging.makeLogRecord({
...     "name": "app",
...     "levelno": logging.INFO,
...     "levelname": "INFO",
...     "msg": "Ready",
... })
>>> os.environ["NO_COLOR"] = "1"
>>> Simple().format(record)
'2026-10-27 13:34:48,899 INFO       [app] Ready'

$ NO_COLOR=1 python app.py

Switch colour on¶

Set FORCE_COLOR, or pass force_styling=True, to keep the colour codes when the output is not a terminal, for example in a CI log viewer that renders them:

>>> formatter = Simple(force_styling=True)
>>> formatter.format(record)
'\x1b[32m2026-10-27 13:34:48,899\x1b[0m \x1b[36mINFO      \x1b[0m \x1b[1m[app]\x1b[0m Ready'

Other formatters¶

The formatters in gouge.parseable never emit colour. A pre-formatter which adds colour codes, such as uvicorn_access(), is covered by the rules above: its codes are removed with all the others when colour is off.