JSON
Reading JSON in C Sharp With System Text Json Defaults
What System.Text.Json does by default in .NET 9: exact-case names, JsonSerializerDefaults.Web, enum surprises, the 64 level depth limit and duplicate keys.
6 min read
Library
Everything you need to level up your coding skills.
JSON
Reading JSON in Java With Jackson Records and Trees
Read JSON in Java with Jackson 2.20: records, JsonNode trees, unknown fields, duplicate keys, the nesting and number limits, and the date trap on writing.
6 min read
JSON
Handling Unknown JSON Fields in Go Without Losing Data
Go ignores unknown JSON members by default. Reject them with DisallowUnknownFields, keep them with a raw map, and see where each option stops working.
6 min read
CSV
Using sqlite utils to Load CSV Fast Into a SQLite Database
Load a CSV into SQLite with one sqlite-utils command, set a primary key, control type detection, add full-text search, and see what 2 million rows cost.
6 min read
CSV
CSVLint and Other Validators for CSV Files Compared
Four CSV validators run on the same broken files: qsv validate, csvkit csvclean, CSVLint and Frictionless. What each reports, how it exits and which to use.
7 min read
CSV
VisiData for Exploring CSV Interactively in the Terminal
Open a CSV in VisiData to scroll, sort, filter and profile it from the keyboard, build frequency tables, and save results, plus its batch mode for scripts.
7 min read
CSV
Using Mlr Miller for Records and Pipelines on the Shell
Miller (mlr) treats CSV rows as named records and chains verbs with then. Real runs for sorting, grouping, new columns, JSON conversion and splitting files.
6 min read
CSV
Using xsv and qsv Side by Side on the Command Line
xsv and qsv share a command set, and qsv adds an index, sniffing, validation and more. See the overlap, the real timings with an index, and the type trap.
7 min read
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
CSV
Handling CSV With Comment Lines and Metadata Headers
Some CSV files carry lines starting with a hash that are notes, not data. Skip them safely, because a comment option can also cut values like Suite #4.
6 min read
CSV
Detecting and Handling Embedded Headers Repeated Mid File
A CSV that repeats its header after every page or section breaks type conversion. Find the repeated lines, drop them safely and check nothing real went too.
6 min read
CSV
Header Variants and Normalizing Column Names in CSV Files
Clean up messy CSV headers into stable column names: BOMs, spaces, case, accents, duplicates, blanks and leading digits, with a function you can test.
7 min read
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