PYTHON
Merge Multiple Dictionaries Efficiently (Python 3.9+)
Explore the modern `|` operator for merging dictionaries in Python 3.9+, offering a clean and efficient way to combine configuration settings or API payloads.
config_defaults = {'theme': 'dark', 'font_size': 14, 'language': 'en'}
user_settings = {'font_size': 16, 'language': 'fr'}
admin_overrides = {'theme': 'light'}
# Merge dictionaries using the | operator (Python 3.9+)
final_config = config_defaults | user_settings | admin_overrides
print(final_config)
# For older Python versions (3.5+), use unpacking:
# final_config_old = {**config_defaults, **user_settings, **admin_overrides}
# print(final_config_old)
How it works: This snippet demonstrates the clean and readable way to merge multiple dictionaries in Python 3.9+ using the `|` union operator. Dictionaries are merged from left to right, meaning later dictionaries' values for common keys will override earlier ones. This is particularly useful for combining default configurations with user-specific settings or admin overrides in web applications, or composing API request bodies from various parts. For Python versions prior to 3.9, the dictionary unpacking operator `**` achieves a similar result.