transformers/main/en/main_classes/logging.md

# Logging

🤗 Transformers has a centralized logging system, so that you can setup the verbosity of the library easily.

Currently the default verbosity of the library is `WARNING`.

To change the level of verbosity, just use one of the direct setters. For instance, here is how to change the verbosity
to the INFO level.

```python
import transformers

transformers.logging.set_verbosity_info()
```

You can also use the environment variable `TRANSFORMERS_VERBOSITY` to override the default verbosity. You can set it
to one of the following: `debug`, `info`, `warning`, `error`, `critical`, `fatal`. For example:

```bash
TRANSFORMERS_VERBOSITY=error ./myprogram.py
```

Additionally, some `warnings` can be disabled by setting the environment variable
`TRANSFORMERS_NO_ADVISORY_WARNINGS` to a true value, like *1*. This will disable any warning that is logged using
`logger.warning_advice`. For example:

```bash
TRANSFORMERS_NO_ADVISORY_WARNINGS=1 ./myprogram.py
```

Here is an example of how to use the same logger as the library in your own module or script:

```python
from transformers.utils import logging

logging.set_verbosity_info()
logger = logging.get_logger("transformers")
logger.info("INFO")
logger.warning("WARN")
```

All the methods of this logging module are documented below, the main ones are
[logging.get_verbosity()](/docs/transformers/main/en/main_classes/logging#transformers.utils.logging.get_verbosity) to get the current level of verbosity in the logger and
[logging.set_verbosity()](/docs/transformers/main/en/main_classes/logging#transformers.utils.logging.set_verbosity) to set the verbosity to the level of your choice. In order (from the least
verbose to the most verbose), those levels (with their corresponding int values in parenthesis) are:

- `transformers.logging.CRITICAL` or `transformers.logging.FATAL` (int value, 50): only report the most
  critical errors.
- `transformers.logging.ERROR` (int value, 40): only report errors.
- `transformers.logging.WARNING` or `transformers.logging.WARN` (int value, 30): only reports error and
  warnings. This is the default level used by the library.
- `transformers.logging.INFO` (int value, 20): reports error, warnings and basic information.
- `transformers.logging.DEBUG` (int value, 10): report all information.

By default, `tqdm` progress bars will be displayed during model download. [logging.disable_progress_bar()](/docs/transformers/main/en/main_classes/logging#transformers.utils.logging.disable_progress_bar) and [logging.enable_progress_bar()](/docs/transformers/main/en/main_classes/logging#transformers.utils.logging.enable_progress_bar) can be used to suppress or unsuppress this behavior.

## `logging` vs `warnings`[[transformers.utils.logging.captureWarnings]]

Python has two logging systems that are often used in conjunction: `logging`, which is explained above, and `warnings`,
which allows further classification of warnings in specific buckets, e.g., `FutureWarning` for a feature or path
that has already been deprecated and `DeprecationWarning` to indicate an upcoming deprecation.

We use both in the `transformers` library. We leverage and adapt `logging`'s `captureWarnings` method to allow
management of these warning messages by the verbosity setters above.

What does that mean for developers of the library? We should respect the following heuristics:

- `warnings` should be favored for developers of the library and libraries dependent on `transformers`
- `logging` should be used for end-users of the library using it in every-day projects

See reference of the `captureWarnings` method below.

#### transformers.utils.logging.captureWarnings[[transformers.utils.logging.captureWarnings]]

[Source](https://github.com/huggingface/transformers/blob/main/src/transformers/utils/logging.py#L136)

Calls the `captureWarnings` method from the logging library to enable management of the warnings emitted by the
`warnings` library.

Read more about this method here:
https://docs.python.org/3/library/logging.html#integration-with-the-warnings-module

All warnings will be logged through the `py.warnings` logger.

Careful: this method also adds a handler to this logger if it does not already have one, and updates the logging
level of that logger to the library's root logger.

## Base setters[[transformers.utils.logging.set_verbosity_error]]

#### transformers.utils.logging.set_verbosity_error[[transformers.utils.logging.set_verbosity_error]]

[Source](https://github.com/huggingface/transformers/blob/main/src/transformers/utils/logging.py#L230)

Set the verbosity to the `ERROR` level.

#### transformers.utils.logging.set_verbosity_warning[[transformers.utils.logging.set_verbosity_warning]]

[Source](https://github.com/huggingface/transformers/blob/main/src/transformers/utils/logging.py#L220)

Set the verbosity to the `WARNING` level.

#### transformers.utils.logging.set_verbosity_info[[transformers.utils.logging.set_verbosity_info]]

[Source](https://github.com/huggingface/transformers/blob/main/src/transformers/utils/logging.py#L215)

Set the verbosity to the `INFO` level.

#### transformers.utils.logging.set_verbosity_debug[[transformers.utils.logging.set_verbosity_debug]]

[Source](https://github.com/huggingface/transformers/blob/main/src/transformers/utils/logging.py#L225)

Set the verbosity to the `DEBUG` level.

## Other functions[[transformers.utils.logging.get_verbosity]]

#### transformers.utils.logging.get_verbosity[[transformers.utils.logging.get_verbosity]]

[Source](https://github.com/huggingface/transformers/blob/main/src/transformers/utils/logging.py#L173)

Return the current level for the 🤗 Transformers's root logger as an int.

🤗 Transformers has following logging levels:

- 50: `transformers.logging.CRITICAL` or `transformers.logging.FATAL`
- 40: `transformers.logging.ERROR`
- 30: `transformers.logging.WARNING` or `transformers.logging.WARN`
- 20: `transformers.logging.INFO`
- 10: `transformers.logging.DEBUG`

**Returns:**

``int``

The logging level.

#### transformers.utils.logging.set_verbosity[[transformers.utils.logging.set_verbosity]]

[Source](https://github.com/huggingface/transformers/blob/main/src/transformers/utils/logging.py#L196)

Set the verbosity level for the 🤗 Transformers's root logger.

**Parameters:**

verbosity (`int`) : Logging level, e.g., one of:  - `transformers.logging.CRITICAL` or `transformers.logging.FATAL` - `transformers.logging.ERROR` - `transformers.logging.WARNING` or `transformers.logging.WARN` - `transformers.logging.INFO` - `transformers.logging.DEBUG`

#### transformers.utils.logging.get_logger[[transformers.utils.logging.get_logger]]

[Source](https://github.com/huggingface/transformers/blob/main/src/transformers/utils/logging.py#L159)

Return a logger with the specified name.

This function is not supposed to be directly accessed unless you are writing a custom transformers module.

#### transformers.utils.logging.enable_default_handler[[transformers.utils.logging.enable_default_handler]]

[Source](https://github.com/huggingface/transformers/blob/main/src/transformers/utils/logging.py#L244)

Enable the default handler of the HuggingFace Transformers's root logger.

#### transformers.utils.logging.disable_default_handler[[transformers.utils.logging.disable_default_handler]]

[Source](https://github.com/huggingface/transformers/blob/main/src/transformers/utils/logging.py#L235)

Disable the default handler of the HuggingFace Transformers's root logger.

#### transformers.utils.logging.enable_explicit_format[[transformers.utils.logging.enable_explicit_format]]

[Source](https://github.com/huggingface/transformers/blob/main/src/transformers/utils/logging.py#L290)

Enable explicit formatting for every HuggingFace Transformers's logger. The explicit formatter is as follows:
```
    [LEVELNAME|FILENAME|LINE NUMBER] TIME >> MESSAGE
```

All handlers currently bound to the root logger are affected by this method.

#### transformers.utils.logging.reset_format[[transformers.utils.logging.reset_format]]

[Source](https://github.com/huggingface/transformers/blob/main/src/transformers/utils/logging.py#L305)

Resets the formatting for HuggingFace Transformers's loggers.

All handlers currently bound to the root logger are affected by this method.

#### transformers.utils.logging.enable_progress_bar[[transformers.utils.logging.enable_progress_bar]]

[Source](https://github.com/huggingface/transformers/blob/main/src/transformers/utils/logging.py#L410)

Enable tqdm progress bar.

#### transformers.utils.logging.disable_progress_bar[[transformers.utils.logging.disable_progress_bar]]

[Source](https://github.com/huggingface/transformers/blob/main/src/transformers/utils/logging.py#L417)

Disable tqdm progress bar.