Limit Output
============


Description
-----------

This extension limits the number of characters a codecell will output as text
or HTML.
This also allows the interruption of endless loops of print commands.

[![Demo Video](https://img.youtube.com/vi/U26ujuPXf00/0.jpg)](https://youtu.be/U26ujuPXf00)

You can set the number of characters using the ConfigManager:

```python
from notebook.services.config import ConfigManager
cm = ConfigManager().update('notebook', {'limit_output': 1000})
```

or by using the [jupyter_nbextensions_configurator](https://github.com/Jupyter-contrib/jupyter_nbextensions_configurator)

The limit can also be set for an individual cell, using the cell's
`cell.metadata.limit_output`.


Internals
---------

Three types of messages are intercepted: `stream`, `execute_result`, and
`display_data`. For `stream`-type messages, the text string length is limited
to `limit_output` number of characters.
For other message types, `text/plain` and `text/html` content length is
counted, and if either exceeds `limit_output` characters will be truncated to
`limit_output` number of characters.

The `limit_output_message` parameter can be formatted to display the
`limit_output` length and the current `output_length`, using the respective
replacement fields `{limit_output_length}` and `{output_length}`.

### Parameter Overview

* limit_output - Number of characters to limit output to
* limit_stream - Enable limiting stream messages
* limit_execute_result - Enable limiting execute_result messages
* limit_display_data - Enable limiting display_data messages
* limit_output_message - Message to append when output is limited