JSON
Unnesting JSON Arrays in BigQuery With JSON_QUERY_ARRAY
Turn a JSON array into rows in BigQuery with UNNEST and JSON_QUERY_ARRAY or JSON_VALUE_ARRAY, with positions, empty arrays, nesting and filters.
7 min read
Library
Everything you need to level up your coding skills.
Excel
Hidden Sheets and Metadata Leaking Out of Shared Workbooks
Find hidden sheets, document properties, comments, defined names and pivot caches in a workbook before you share it, with a script that audits the file.
7 min read
CSV
Reading a CSV File in Kotlin for a Quick Import Job
Read a CSV in Kotlin with kotlin-csv and build a small import job that validates rows, rejects bad ones with row numbers and never hides a failure.
11 min read
XML
Versioning an XML Format Without Breaking Existing Readers
Version attribute or new namespace? Test results show how strict schemas reject added elements and how an extension point lets old readers keep working.
6 min read
Excel
Macros and Why Data Teams Should Block Them by Default
Compare xlsx, xlsm, xls and xlsb for data work, and set a policy that blocks macros by default while allowing reviewed exceptions with a real owner.
7 min read
CSV
Reading CSV Files in Bash Without Breaking on Quotes
A bash read loop on a CSV breaks on quoted commas, backslashes, a missing last newline and empty tab fields. Let a CSV parser emit safe records first.
10 min read
YAML
Billion Laughs Style Attacks Through YAML Aliases Tested
Build a 378-byte YAML document that expands to 34 MB, measure PyYAML, DuckDB and Go on it, and see which parsers fail early and which wait for the output.
7 min read
JSON
Extracting JSON Fields in BigQuery With JSON_VALUE
Read JSON in BigQuery with JSON_VALUE, JSON_QUERY, field access and typed converters such as INT64(), with the null rules, SAFE prefix and lax conversion.
7 min read
CSV
Parsing CSV in Ruby With the CSV Library and Its Converters
Parse CSV in Ruby 3.4 with the csv gem: the Gemfile LoadError, a numeric converter that read 02134 as 1116, nil versus empty strings, and timings.
10 min read
Excel
Formula Injection in Excel Exports and How to Stop It
Stop formula injection in xlsx exports: write user text as strings with openpyxl or XlsxWriter, neutralize leading =, +, - and @ characters, and test it.
7 min read
XML
When XML Attributes Are the Better Choice Over Elements
Attributes suit short identifying values, elements suit everything with structure or long text. A test of the whitespace and ordering rules shows why.
6 min read
CSV
Reading a CSV File in PHP With fgetcsv and SplFileObject
Read CSV in PHP 8.5 with fgetcsv and SplFileObject: the $escape deprecation, a backslash that swallows the file, str_getcsv traps and the BOM.
10 min read
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