https://github.com/pomponchik/displayhooks
Extend the capabilities of the standard displayhook in Python
https://github.com/pomponchik/displayhooks
displayhook printing python-repl repl
Last synced: 2 days ago
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Extend the capabilities of the standard displayhook in Python
- Host: GitHub
- URL: https://github.com/pomponchik/displayhooks
- Owner: pomponchik
- License: mit
- Created: 2024-08-26T11:15:49.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2025-11-19T12:35:21.000Z (3 months ago)
- Last Synced: 2025-11-27T17:48:45.930Z (3 months ago)
- Topics: displayhook, printing, python-repl, repl
- Language: Python
- Homepage:
- Size: 34.2 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# displayhooks
[](https://pepy.tech/project/displayhooks)
[](https://pepy.tech/project/displayhooks)
[](https://coveralls.io/github/pomponchik/displayhooks?branch=main)
[](https://github.com/boyter/scc/)
[](https://hitsofcode.com/github/pomponchik/displayhooks/view?branch=main)
[](https://github.com/pomponchik/metronomes/actions/workflows/tests_and_coverage.yml)
[](https://pypi.python.org/pypi/displayhooks)
[](https://badge.fury.io/py/displayhooks)
[](http://mypy-lang.org/)
[](https://github.com/astral-sh/ruff)
It's a micro library for manipulating [`sys.displayhook`](https://docs.python.org/3/library/sys.html#sys.displayhook).
When you need to change the standard behavior of `displayhook`, with this library you will do it:
- 💎 declaratively
- 🫥 compactly
- 🌞 beautifully
## Table of contents
- [**Quick start**](#quick-start)
- [**Change the displayed value**](#change-the-displayed-value)
- [**Prohibiting the display of certain types of values**](#prohibiting-the-display-of-certain-types-of-values)
- [**Automatic recovery of the default hook**](#automatic-recovery-of-the-default-hook)
## Quick start
Install it:
```bash
pip install displayhooks
```
And use:
```python
import sys
from displayhooks import not_display
not_display(int)
sys.displayhook('Most of the adventures recorded in this book really occurred; one or two were experiences of my own, the rest those of boys who were schoolmates of mine.')
#> 'Most of the adventures recorded in this book really occurred; one or two were experiences of my own, the rest those of boys who were schoolmates of mine.'
sys.displayhook(666)
# [nothing!]
```
## Change the displayed value
You can declaratively declare a converter function for the printed values. What it returns will be used to call the original `displayhook` function.
```python
import sys
from displayhooks import converted_displayhook
@converted_displayhook
def new_displayhook(value):
return value.lower()
sys.displayhook("What’s gone with that boy, I wonder? You TOM!")
#> 'what’s gone with that boy, i wonder? you tom!'
```
If your function returns `None`, nothing will be printed.
## Prohibiting the display of certain types of values
You can disable the display of certain data types, similar to how [`NoneType`](https://docs.python.org/3/library/types.html#types.NoneType) values are ignored by default.
You could already see a similar example above, let's look at it again:
```python
import sys
from types import FunctionType
from displayhooks import not_display
not_display(FunctionType)
sys.displayhook('Nothing! Look at your hands. And look at your mouth. What is that truck?')
#> 'Nothing! Look at your hands. And look at your mouth. What is that truck?'
sys.displayhook(lambda x: x)
# [nothing!]
```
In this example, you can see that we have disabled the display for functions, but all other data types are displayed unchanged.
## Automatic recovery of the default hook
You can limit the impact on [`sys.displayhook`](https://docs.python.org/3/library/sys.html#sys.displayhook) only to the code inside a function. If you hang the `autorestore_displayhook` decorator on it, after exiting the function, the displayhook that was installed before it was called will be automatically restored:
```python
import sys
from types import FunctionType
from displayhooks import not_display, autorestore_displayhook
@autorestore_displayhook
def do_something_dangerous():
not_display(FunctionType)
sys.displayhook(do_something_dangerous)
# [nothing!]
do_something_dangerous()
sys.displayhook(do_something_dangerous)
#>
```