YAML
A Cheat Sheet of YAML Syntax for Everyday Config Files
One page of YAML syntax: scalars, quoting, collections, block strings, anchors, documents, comments and the values that change type. Copy-ready snippets.
6 min read
Tag
cheatsheet
14 posts
CSVGuide
CSV Tools Worth Knowing and When to Reach for Each One
A field guide to CSV tools: csvkit, qsv, Miller, DuckDB, sqlite-utils, Polars, pandas and VisiData, run on the same 2 million row file with timings.
18 min read
CSVGuide
CSV Dialects and Variants You Will Run Into in Practice
The CSV dialects that exist in the wild, from RFC 4180 and Excel to PostgreSQL text, MySQL, TSV and pipes, with the settings that tell them apart.
19 min read
JSONGuide
JSON in Go Java Rust C Sharp PHP Ruby Compared Side by Side
One order document read in Go, Java, Rust, C#, PHP, Ruby, Python, Node and Bash: unknown keys, case, nulls, big ints, depth, duplicates and strictness.
18 min read
ExcelGuide
Excel Formulas Data People Use Every Week Explained
The Excel formulas data people use every week: lookups, conditional sums, text and date cleanup, arrays, errors and LET, with their SQL equivalents.
19 min read
CSVGuide
Exporting Query Results to CSV From Five Major Databases
The same eight awkward rows exported from PostgreSQL, MySQL, SQLite, DuckDB and MongoDB, then read back: four tools return all 8, one recipe returns 4.
25 min read
YAMLGuide
Parsing YAML in Languages Other Than Python Compared
One YAML document parsed in Node, Go, Java, Ruby, PHP, Rust, C# and yq: types, dates, duplicate keys, strict modes, safety and parse speed, all measured.
17 min read
ExcelGuide
Reading and Writing Excel From JavaScript Java and C Sharp
Cross language reference for reading and writing xlsx in JavaScript, Java, C Sharp, PHP, R, Go, Ruby and Rust: libraries, types, dates, memory and security.
17 min read
Editor's pick
CSVGuide
Reading CSV Files in Go Java R Rust and C Sharp Compared
Ten languages read the same awkward CSV files: speed on 2,000,000 rows, BOM, bad quotes, ragged rows, leading zeros and defaults that bite, plus a test list.
18 min read
XMLGuide
Parsing XML in Java C Sharp and Other Typed Languages
One XML file and one task in eight languages, with each output, the defaults that change your data, and how each treats absent, empty and bad values.
17 min read
Excel
Fixing Circular Reference Warnings in Imported Sheets
Why imported Excel sheets warn about circular references, how to find the loop with the trace tools, and the fix for each cause in formulas and scripts.
7 min read
XMLGuide
Common XML Formats You Will Meet in Real Work Reference
A reference to the XML formats you meet in practice: how to recognize each by root and namespace, what to extract, and the trap each one carries.
19 min read