Today I Learned (TILs)

Short technical notes, quick tips, and things I’ve learned along the way. These are bite-sized learnings that don’t warrant a full blog post but are worth remembering and sharing. Sometimes it’s just a single Linux command I want to remember for next time.

How to stop Claude Code adding Co-Authored-By to your commits

24 September 2026·6 mins

One setting removes the attribution trailer at the source. A PreToolUse hook is the backstop - with one gotcha that made mine reject my own grep.

How to run one specific pytest test from the command line

27 June 2026·2 mins

Six ways to narrow pytest to a single test - by file, class, method, parametrisation, keyword, or last-failed.

Commas and Dots Mean Different Things in Different Locales

22 April 2026·2 mins

Why 1,234.56 and 1.234,56 are the same number depending on where you are

How to diff two large JSON files with out-of-order keys

11 March 2026·2 mins

diff gives you noise. jq -S, dyff, and jd give you the actual semantic difference.

How to convert a file from CP1250 to UTF-8 with iconv

7 March 2026·2 mins

One iconv command to convert files between character encodings (CP1250, ISO-8859, UTF-16) - plus the ones you’ll actually encounter.