pyhanko.pdf_utils.config_utils module

This module contains utilities for allowing dataclasses to be populated by user-provided configuration (e.g. from a Yaml file).

Note

On naming conventions: this module converts hyphens in key names to underscores as a matter of course.

exception pyhanko.pdf_utils.config_utils.ConfigurationError

Bases: ValueError

Signal configuration errors.

class pyhanko.pdf_utils.config_utils.ConfigurableMixin

Bases: object

General configuration mixin for dataclasses

classmethod process_entries(config_dict)

Hook method that can modify the configuration dictionary to overwrite or tweak some of their values (e.g. to convert string parameters into more complex Python objects)

Subclasses that override this method should call super().process_entries(), and leave keys that they do not recognise untouched.

Parameters

config_dict – A dictionary containing configuration values.

Raises

ConfigurationError – when there is a problem processing a relevant entry.

classmethod from_config(config_dict)

Attempt to instantiate an object of the class on which it is called, by means of the configuration settings passed in.

First, we check that the keys supplied in the dictionary correspond to data fields on the current class. Then, the dictionary is processed using the process_entries() method. The resulting dictionary is passed to the initialiser of the current class as a kwargs dict.

Parameters

config_dict – A dictionary containing configuration values.

Returns

An instance of the class on which it is called.

Raises

ConfigurationError – when an unexpected configuration key is encountered or left unfilled, or when there is a problem processing one of the config values.