pescador

Pescador is a library for streaming (numerical) data, primarily for use in machine learning applications.

Pescador addresses the following use cases:

These use cases arise in the following common scenarios:

Say you have three data sources (A, B, C) that you want to sample. For example, each data source could contain all the examples of a particular category.

Pescador can dynamically interleave these sources to provide a randomized stream D <- (A, B, C). The distribution over (A, B, C) need not be uniform: you can specify any distribution you like!
Now, say you have 3000 data sources, each of which may contain a large number of samples. Maybe that's too much data to fit in RAM at once.

Pescador makes it easy to interleave these sources while maintaining a small working set. Not all sources are simultaneously active, but Pescador manages the working set so you don't have to.
If loading data incurs substantial latency (e.g., due to accessing on-disk storage or pre-processing), this can be a problem.

Pescador can seamlessly move data generation into a background process, so that your main thread can continue working.

Installation

Pescador can be installed from PyPI through pip:

pip install pescador

or with conda using the conda-forge channel:

conda install -c conda-forge pescador