Uwe’s Blog

My writing about data engineering, opensource development, general programming and thoughts about engineering culture.

  • Writing a boolean array for pandas that can deal with missing values

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    When working with missing data in pandas, one often runs into issues as the main way is to convert data into float columns. pandas provides efficient/native support for boolean columns through the numpy.dtype('bool'). Sadly, this dtype only supports True/False as possible values and no possibility for storing missing...

  • Data Engineers: The best friends of Data Scientists you forgot to hire.

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    At the moment in Computer Science, there are two hot topics: AI and Blockchain. Behind these two buzzwords, there are industries striving to build successful products. Currently, I work in the sector often labelled as AI. Usually, it is also described with other terms like Machine Learning or Big Data. In this sector the currently most sought-after job is the...

  • Data Science I/O - A baseline benchmark for 2019

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    Data Science and Machine Learning are tasks that have their own requirements on I/O. As many other tasks, they start out on tabular data in most cases. In contrast to a typical reporting task, they don’t work on aggregates but require the data on the most granular level. Some machine learning algorithms are able to directly work on aggregates but...

  • PyFlame: profiling running Python processes

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    Identifying performance bottlenecks in long-running processes often involves careful instrumentation ahead or guessing where the root of the problem may be. A very welcome set of tools are the ones that help you diagnose problems of live systems without modifying them. One important tool I recently came across is the pyflame profiler.

  • Use Numba to work with Apache Arrow in pure Python

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    Apache Arrow is an in-memory memory format for columnar data. In more “plain” English, it is a standard on how to store DataFrames/tables in memory, independent of the programming language. One of its most prominent uses is for the @pandas_udf decorator in Apache Spark to move data quickly between Scala and Python/pandas.

  • AHL Python Hackathon April 2018

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    Three weeks ago MAN AHL organised an opensource hackathon at their London office. As part of the Hackathon people should contribute to one of the PyData artifacts they regularly use. To support them in making their first contribution, AHL also coordinated that several core committers of opensource projects were present at the event. I joined in as the representative...

  • Use Media Keys to control Tomahawk in Awesome WM

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    Nowadays for controling a mediaplayer the MPRIS specification exists, sadly this interface seems unsupported by awesome. One solution would be to add some lines to the configuration of xbindkeys and to start it in the background. But as awesome already can handle global keybindings adding these lines to your .config/awesome/rc.lua will transmit the actions of...