Today I Learned: pytest output

Getting pytest to display output, even if the test case passes; sorting tuples by datetime

Frequently, I find myself needing to watch print statements during development as pytest calls new methods. Today I learned how to force passing tests to write to the screen. The -rP option is the answer to that. I'm constantly impressed with how much pytest just already has implemented.

Along the vein of 'wow, it just works', I was surprised to find how easy it was to sort tuples by date. On a side note, the StackOverflow question linked to in the previous sentence closed as a duplicate, and I don't think it should have been. I mean sure, there was a more general question that could be construed to be the answer if you already knew lots of Python, but that's kind of beside the point I think. If I knew enough python to make the construction, I probably wouldn't have asked the question. I mean I didn't ask that actual question, but you get the idea.

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Now available as a Kindle ebook for 99 cents ! Get a spiffy ebook, and fund more physics The following is a pretty lengthy procedure, but converting the divergence, (nabla, del) operator between coordinate systems comes up pretty often. While there are tables for converting between common coordinate systems , there seem to be fewer explanations of the procedure for deriving the conversion, so here goes! What do we actually want? To convert the Cartesian nabla to the nabla for another coordinate system, say… cylindrical coordinates. What we’ll need: 1. The Cartesian Nabla: 2. A set of equations relating the Cartesian coordinates to cylindrical coordinates: 3. A set of equations relating the Cartesian basis vectors to the basis vectors of the new coordinate system: How to do it: Use the chain rule for differentiation to convert the derivatives with respect to the Cartesian variables to derivatives with respect to the cylindrical variables. The chain ...

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Copasetic Flow

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