pypersist 0.5

Persistent memoisation framework for Python

pypersist
=========

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pypersist is a persistent memoisation framework for Python 3. Persistent
memoisation is the practice of storing the output of a function permanently to a
disk or a server so that the result can be looked up automatically in the
future, avoiding any known results being recomputed unnecessarily.

Installation
------------
pypersist is available from PyPI, and the latest release can be installed using,
for example:

pip3 install --user pypersist

Alternatively, the latest development version can be installed using Github:

git clone https://github.com/mtorpey/pypersist.git
pip3 install --user ./pypersist

Examples
--------
To use, import the `persist` class from the `pypersist` package:

```python
from pypersist import persist
```

and use it as a decorator when writing a function:

```python
@persist
def double(x):
return x * 2

print(double(3))
print(double(6.5))
```

This will store the outputs of the `double` function in a directory called
`persist/double/`, in a machine-readable format.

One can specify various arguments to `persist`. For example:

```python
@persist(key=lambda x,y: (x,y),
hash=lambda k: '%s_to_the_power_of_%s' % k,
pickle=str,
unpickle=int)
def power(x, y):
return x ** y

print(power(2,4))
print(power(10,5))
```

will store the outputs of `power` in human-readable files with descriptive
filenames.

Many more options are available. See the `persist` class documentation for a
full description, or [launch the included notebook on
Binder](https://mybinder.org/v2/gh/mtorpey/pypersist/master?filepath=binder/demo.ipynb)
for more examples.

See [this HackMD](https://hackmd.io/1M5clex-TYWCuxxgi05k5A) and the Issue
tracker for current plans.

pypersist is a part of the OpenDreamKit project: https://opendreamkit.org/