Topic

YAML

Config files that look friendly until the indentation bites. Parsing it, linting it and avoiding its type surprises.

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

YAML

YAML 1.1 Versus 1.2 and Why the Difference Really Matters

The same 33 scalar values loaded by a 1.1 parser and a 1.2 parser: booleans, octal, base 60 and floats. Which libraries implement which, and how to stay safe.

5 min read

YAML

YAML Null Values and the Empty String Question Answered

Six ways to write null in YAML, how they differ from the empty string, and what a key with no value, an empty list and an absent key mean to your code.

6 min read

YAML

Comments in YAML and What Parsers Do With Them in Practice

YAML allows comments with a hash, but most parsers throw them away when they load and save. What survives a round trip in PyYAML, ruamel.yaml and yq.

6 min read

YAML

Round Tripping YAML Without Losing Comments or Order

Edit a YAML file in code and keep its comments, anchors and quotes. PyYAML drops them, ruamel.yaml and yq keep them, and each changes some whitespace.

6 min read

YAML

YAML Anchors Aliases and Merge Keys Without Surprises

Define a block once with an anchor, reuse it with an alias, and merge it with the merge key. Real output shows overrides, sharing and where merging stops.

5 min read

YAML

YAML Lists and Mappings Without Confusion in Real Files

Block and flow styles for sequences and mappings, lists of mappings, empty collections and why a missing value is None, each with its parsed result.

6 min read

YAML

YAML Multiline Strings With Pipe and Greater Than Signs

The pipe keeps line breaks, the greater than sign folds them, and chomping indicators control the final newline. Six variants and the exact strings.

5 min read

YAML

YAML Strings Quoting and When You Really Need Quotes

Plain, single quoted and double quoted YAML strings compared, with the characters that force quotes and a table of values that silently change type.

5 min read

YAML

YAML Indentation Rules and Why Tabs Break Everything

How YAML uses spaces to build structure, why a tab is rejected, and how one extra space turns a sibling into a child. Real parser output for each case.

6 min read

YAML

Converting YAML to a Markdown Table for Docs and READMEs

Generate a Markdown table from a YAML list in Python, escaping pipes, joining lists, handling blanks and keeping the table in sync with the YAML in CI.

6 min read

YAML

Converting an Excel Sheet of Settings Into YAML Using Python

Read a key, value and type sheet with openpyxl, build nested YAML from dotted keys, and keep versions, dates and blanks from changing on the way.

7 min read

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