The first step in any data-intensive project is understanding the available data. To this end, data scientists spend a significant part of their time carrying out data quality assessments and data exploration. In spite of this being a crucial step, it usually requires repeating a series of menial tasks before the data scientist gains an understanding of the dataset and can progress to the next steps in the project.
In this talk I will present Lens (https://github.com/asidatascience/lens), a Python package which automates this drudge work, enables efficient data exploration, and kickstarts data science projects. A summary is generated for each dataset, including:
- General information about the dataset, including data quality of each of the columns;
- Distribution of each of the columns through statistics and plots (histogram, CDF, KDE), optionally grouped by other categorical variables;
- 2D distribution between pairs of columns;
- Correlation coefficient matrix for all numerical columns.
Building this tool has provided a unique view into the full Python data stack, from the parallelised analysis of a dataframe within a Dask custom execution graph, to the interactive visualisation with Jupyter widgets and Plotly. During the talk, I will also introduce how Dask works, and demonstrate how to migrate data pipelines to take advantage of its scalable capabilities.