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Record Shaping with CData

Introduction In many data science projects we have the data, but it “is in the wrong format.” Fortunately re-formatting or reshaping data is a solved problem, with many different available tools. For this note, I would like to show how to reshape data using the data algebra‘s cdata data reshaping […]

Data Algebra over Polars Ready for Production Use

The data algebra is a system for composing data manipulation tasks in Python. In the data algebra, operator pipelines (or even directed acyclic graphs) are the primary objects. Applying operations composes small data pipelines into larger ones. This allows the fluid specification, inspection, and sharing of data processing and data […]

Method Warnings

Introduction The data algebra is a Python system for designing data transformations that can be used in Pandas or SQL. The new 1.3.0 version introduces a lot of early checking and warnings to make designing data transforms more convenient and safer. An Example I’d like to demonstrate some of these […]

How to Re-Map Many Columns in a Database

Introduction A surprisingly tricky problem in doing data science or analytics in the database are situations where one has to re-map a large number of columns. This occurs, for example, in the vtreat data preparation system. In the vtreat case, a large number of the variable encodings reduce to table-lookup […]

Data Algebra Method Catalog

The data algebra is a system for specifying data transformations in Pandas or SQL databases. To use it, we advise checking out the README and introduction. These document what data operators are the basis of data algebra transformation construction and composition. I have now added a catalog of what expression […]

Data Algebra 0.9.0 Release

I am pleased to announce the 0.9.0 release of the data algebra. The data algebra is realization of the Codd relational algebra for data in written in terms of Python method chaining. It allows the concise clear specification of useful data transforms. Some examples can be found here. Benefits include […]