Squash Pickle

Like a pickle, only smaller*.

Tiny python package that compresses your pickles using gzip. Quacks like a pickle.

* For small objects (< 100 bytes) gzip overhead can end up increasing size. Only squash your pickles when you are working with big objects.

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Getting Started

First install the package, this has no additional dependencies:

pip install squashpickle

Then simply replace your pickle calls with sqaushpickle ones. squashpickle implements, dump, dumps, load, and loads functions.

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Performance

The GZIP compression can have a HUGE impact on large objects. Say you are pickling something like a polars / pandas dataframe, these pickles may end up being hundreds of MBs. With squashpickle can get compression ratios exceeding 10x.

For example if we load a large dataframe of australian weather data. Using pickle this object serialises to 37794198 bytes (~37.8MB). Dumping the same dataframe with squashpickle results in 3370363 bytes (~3.4MB), around 9% of the overall file.

import polars as pl
import pickle
import squashpickle

df = pl.read_csv(r"C:\temp\weatherAUS.csv", null_values=["NA"])
print(len(pickle.dumps(df)), len(squashpickle.dumps(df)))

As with any compression, there is a performance cost to achieving the smaller files. For objects <1MB this is hardly noticeable, but for objects hundreds of MBs the delay can be significant. It'll depend on your use case if this is a worthwhile tradeoff.