logger

Algan’s library logger, backed by Python’s standard logging module.

All of Algan’s diagnostic and progress output goes through the "algan" logger. By default it prints bare messages to stderr at INFO level (so render-progress messages stay visible, as they always were). To quiet or raise verbosity, either:

• set the ALGAN_LOG_LEVEL environment variable (e.g. ALGAN_LOG_LEVEL=WARNING silences progress output), or

• call set_log_level() at any time, or

• attach your own handlers to logging.getLogger("algan") after calling logger.handlers.clear().

Levels are thresholds, not selectors: a level shows itself and everything more severe, so INFO also shows warnings and errors.

Algan adds one level of its own, PERF, between DEBUG and INFO:

ALGAN_LOG_LEVEL = PERF  # or set_log_level("PERF")

It carries the renderer’s self-healing events – the batch splits and pool retries it performs when a chunk does not fit. Those are the memory model working as designed, not faults, so they are below INFO and invisible by default; they used to be WARNING, which made a healthy render look broken and was the only thing left on screen for anyone who set WARNING to quiet the progress output. Turn PERF on when a render is slower than expected and you want to see how it is being budgeted. Being below INFO, it also means DEBUG includes these messages.

How a render reports its progress is a separate choice from whether it is logged at all, and is controlled by set_progress_style() or the ALGAN_PROGRESS environment variable – see PROGRESS_STYLES.

Functions

apply_environment_logging()

Apply ALGAN_LOG_LEVEL and ALGAN_PROGRESS to the live logger.

Called once as this module is imported, and again by the render daemon at the start of each run (algan.daemon.execute) so a warm process reports at the verbosity the client asked for. That second call is what makes both variables honestly live rather than baked in at import: neither configures anything a kernel or a module-level default could have frozen – the level lives on a logging.Logger and the style in a module global, and set_log_level() / set_progress_style() move both at any time – so refusing a warm run over a difference in one would be refusing over nothing.

An unset variable resets its setting to the shipped default rather than being skipped. That is what makes the daemon call safe: neither of these lives in SETTINGS.snapshot(), so reset_state() does not restore them, and skipping the unset case would leave one client’s ALGAN_LOG_LEVEL=DEBUG running every later client’s script.

A bad value is reported through the logger and otherwise ignored, on the same principle as every other environment read: a mistyped diagnostic knob must not abort a render.

get_logger(name=None)

Return Algan’s logger, or a child of it when name is given.

get_progress_style()

Return the configured progress style, one of PROGRESS_STYLES.

resolve_progress_style()

Resolve the configured style to a concrete one for this render.

Returns "bar", "log" or "none"; "auto" never survives.

Under "auto" the question being answered is not “is this a terminal” but “will whatever reads stderr act on a carriage return”. Those differ, and isatty() is only a proxy: a captured CI or pytest log has one kept verbatim, while several consoles that are not terminals (PyCharm’s run console, a notebook) render one correctly. So capture is ruled out first, then a terminal is taken at its word, then the known bar-capable consoles get their exception.

set_log_level(level)

Set the verbosity of Algan’s console output.

Parameters:

level – A standard logging level name or value, e.g. "WARNING" to silence progress messages or "DEBUG" for extra detail. Algan’s own "PERF" (see PERF) sits between the two and adds the renderer’s budget and recovery diagnostics to the default output.

Notes

This also holds the noisier third-party loggers Algan pulls in (currently Manim’s) to the same level, so one call quiets the whole console.

set_progress_style(style)

Set how renders report progress.

Parameters:

style – One of PROGRESS_STYLES: "bar", "log", "none" or "auto" (the default).

Raises:

ValueError – If style is not one of PROGRESS_STYLES.

Notes

Progress output is emitted at INFO, so set_log_level("WARNING") silences it whatever the style.