4 posts tagged with "yaml"

Python's PyYAML library is a powerful tool for working with YAML, but it has one common limitation: when you load a YAML file and dump it back, it doesn't preserve the original formatting. This can be a problem if you have multi-line strings formatted as literal blocks (|) and want to keep them that way for readability.

Fortunately, there's a straightforward and effective way to solve this by creating a custom representer for PyYAML. This guide will walk you through the process, using the code you provided, to ensure your multi-line strings are always dumped as literal blocks.

No, it is not possible for standard Python YAML libraries like PyYAML to preserve the original literal block format (e.g., | or >) when you load a YAML file and then dump it back. This is because the parser converts the literal block content into a standard Python string, discarding the original formatting. When you dump the string back to YAML, the dumper uses its own rules to represent the string, which typically defaults to a quoted style or a folded block style, but not necessarily the original one.

To define a property that can be a string or null in OpenAPI (Swagger), you use different methods depending on the OpenAPI specification version.

When defining server URLs in OpenAPI specs, you often need to reference environment-specific values (like staging or production subdomains). But using raw environment variables can result in placeholder values like default: unknown, which may confuse tools like Swagger UI, ReDoc, or code generators.

This guide explains the issue and offers clean solutions - with practical examples.