pyaml - Pretty YAML Dumper

26.2.1 · active · verified Thu Apr 09

pyaml is a PyYAML-based module designed to produce more human-readable and aesthetically pleasing YAML-serialized data. It provides enhanced defaults for indentation, key sorting, and block-style formatting. The current version is 26.2.1, and it maintains a moderate release cadence, with updates typically several times a year to reflect PyYAML changes or minor enhancements.

Warnings

gotcha pyaml focuses exclusively on *dumping* (serialization) YAML data. It does not provide `load` or `loads` functionality for deserializing YAML. For deserialization, you must use `PyYAML` directly (e.g., `yaml.safe_load`).
Fix: Use `import yaml` from the underlying PyYAML library for loading operations, e.g., `yaml.safe_load(yaml_string)`.
gotcha While `pyaml` is built on `PyYAML`, its default output behavior (e.g., `sort_keys=True`, specific indentation, preference for block style) differs significantly from `PyYAML`'s raw `dump` defaults. This is its core purpose, but users expecting a drop-in replacement that only visually enhances existing `PyYAML` output might be surprised by structural changes.
Fix: Always test `pyaml` output if migrating from raw `PyYAML` dumping. Most `pyaml.dump` options can be manually configured (e.g., `sort_keys=False`) to revert specific behaviors if desired.
gotcha pyaml requires `PyYAML` to be installed. Although `pip install pyaml` typically installs `PyYAML` as a dependency, it's essential to understand that `pyaml` is a wrapper, not a standalone YAML library. Issues with `PyYAML` (e.g., version conflicts, specific platform issues) can affect `pyaml`.
Fix: Ensure `PyYAML` is correctly installed and compatible. If encountering issues, try updating `PyYAML` or checking its documentation for platform-specific notes.

Install

pip install pyaml Install pyaml

Imports

dump
```
import pyaml
# then use pyaml.dump(...)
```
pyaml provides dump and dumps functions directly under its module namespace.
dumps
```
import pyaml
# then use pyaml.dumps(...)
```
pyaml provides dump and dumps functions directly under its module namespace.

Quickstart

This quickstart demonstrates how to use `pyaml.dump` to write YAML data to a file-like object (like `sys.stdout`) and `pyaml.dumps` to get the formatted YAML as a string. pyaml automatically applies its 'pretty' formatting defaults, including sorted keys and sensible indentation.

import pyaml
import sys

data = {
    'name': 'Alice',
    'age': 30,
    'isStudent': False,
    'courses': [
        {'title': 'Math', 'credits': 3},
        {'title': 'History', 'credits': 4}
    ],
    'address': {
        'street': '123 Main St',
        'city': 'Anytown',
        'zip': '12345'
    }
}

# Dump to stdout with pretty formatting
print('--- Pretty YAML Output (to stdout) ---')
pyaml.dump(data, sys.stdout)

# Or get as a string
yaml_string = pyaml.dumps(data)
print('\n--- Pretty YAML Output (as string) ---')
print(yaml_string)

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