YAML
Environment Variable Substitution in YAML Config Files
Substitute environment variables into YAML config after parsing, not before. Expanding text first broke on a colon and hash; a typed walk kept the value.
6 min read
Tag
how-to
590 posts
MySQL
Running MySQL in Docker With a Data Volume That Persists
Run MySQL 8.4 in Docker with a named volume, environment variables, a custom config, health checks, initialization scripts and safe upgrades.
6 min read
PostgreSQL
Creating Your First Database User and Schema in PostgreSQL
Create your first PostgreSQL role, database and schema: CREATE ROLE with LOGIN, a database with an owner, search_path, and the public schema change.
7 min read
Editor's pick
CSVGuide
Handling CSV Files Too Big to Open in Excel or Python
A decision guide for CSV files too big to open: look, count, sample, query in place, chunk, split, compress or convert, with numbers from a 1.3 GB file.
17 min read
YAML
Reading YAML Front Matter From Markdown Files in Python
Split a Markdown file into YAML metadata and body with one regex, then handle dates, CRLF, a BOM, a missing closing line and body text with dashes.
6 min read
MySQL
Installing MySQL 8.4 on macOS Linux and Windows Step by Step
Install MySQL 8.4 LTS on macOS, Ubuntu and Windows: package sources, first start, the root account, secure setup and checks that the server works.
6 min read
JSON
JSON Data Types and What Is Missing From Them Entirely
JSON has six value types and no date, binary, integer, decimal, set or undefined. See what Python and JavaScript do to each missing type when they serialize.
6 min read
PostgreSQL
Running PostgreSQL in Docker With a Persistent Volume
Run PostgreSQL in Docker with a named volume so data survives restarts, set the password and database on first start, publish the port safely and use Compose.
7 min read
YAML
Merging Two YAML Files in Python With a Deep Merge
dict update is shallow and replaces whole blocks. A 10-line deep merge, the list policy choice and what null means, tested on a base and an override file.
6 min read
MySQLGuide
Getting a MySQL Server Running and Usable From Scratch
A beginner guide to getting a MySQL server running: choose a version, install, secure, connect, create users and fix the first errors.
16 min read
CSV
Round Tripping Exports Back Into Imports Without Drift
A CSV export should re-import to the same data. A test where identical files hid a NULL turned into an empty string, and how to test round trips on rows.
7 min read
PostgreSQL
Installing PostgreSQL on macOS Linux and Windows Today
Install PostgreSQL on macOS with Homebrew, on Linux with packages and on Windows with the installer, then check that the service runs.
7 min read