Excel
Reducing Workbook Size by Removing Unused Styles and Data
Find why an xlsx is large by looking inside the zip, then remove unused styles, empty formatted rows, pivot caches, images and links to shrink the file.
8 min read
Library
Everything you need to level up your coding skills.
XML
Parsing an Atom Feed Into a Database With Safe Upserts
Load an Atom feed into PostgreSQL by entry id with insert or update, read links, categories and html content correctly, and compare lxml with feedparser.
7 min read
CSV
Getting Started With csvkit for Everyday CSV Tasks
csvkit gives you csvcut, csvgrep, csvlook, csvstat, csvsort and csvsql with real CSV parsing. See the everyday commands, inference traps and speed cost.
8 min read
JSON
Expanding JSON Arrays With json_each and json_tree
Turn SQLite JSON arrays and objects into rows with json_each and walk whole documents with json_tree, with every column explained and the edge cases checked.
7 min read
Excel
Analyzing More Than a Million Rows Without Excel Limits
Analyze data beyond Excel's 1,048,576 row limit with DuckDB, SQLite, pandas in chunks or the Data Model, and bring only the summary back to Excel.
6 min read
CSV
Using awk on CSV Files and Where It Gets Dangerous
awk -F, sums and groups a CSV in one pass when nothing is quoted. See the cases where it silently returns wrong fields, and what FPAT does and does not fix.
8 min read
XML
Debugging an XSLT Transform That Outputs Nothing or Too Much
Five stylesheets that output nothing or the whole file as text, with the cause of each: a namespace, a built-in rule, an absolute path, and a literal id.
7 min read
CSV
Selecting CSV Columns With cut and Why Quotes Break It
cut -d, -f picks CSV columns until a quoted comma shifts every field after it. See the failure, a guard that detects it, and CSV-aware replacements.
8 min read
YAML
Loading YAML Seed Data Into PostgreSQL With Python
Load a YAML list into PostgreSQL 18 with psycopg: adapt dates, arrays and jsonb, rerun safely with ON CONFLICT and let constraints reject bad rows.
6 min read
Excel
Converting a Huge Excel File to CSV or Parquet Safely
Convert a very large Excel workbook to CSV or Parquet with a streaming script, DuckDB or LibreOffice, keeping types, dates, encoding and every sheet right.
8 min read
JSON
The SQLite Arrow Operators for JSON Explained With Examples
SQLite's -> and ->> operators read JSON like PostgreSQL and MySQL, with their own rules for bare keys, negative indexes, precedence and the types they return.
7 min read
CSV
Previewing a CSV in the Terminal With column and less
Look at a CSV in the terminal with head, column -t, less -S, csvlook, qsv table and Miller, and learn where each one misleads you on quotes and encodings.
8 min read
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