How do you store Python dictionaries for later use?

Storing Python Dictionaries

Python dictionaries provide a versatile method for organizing data in key-value pairs. To preserve these dictionaries beyond the current program execution, consider storing them as portable files.

JSON and Pickle

Two prevalent options for storing dictionaries are JSON and Pickle. JSON (JavaScript Object Notation) represents data in a human-readable format, while Pickle serializes Python objects into a binary format.

JSON

To store a dictionary as a JSON file, use the json module:

<code class="python">import json

with open('data.json', 'w') as fp:
    json.dump(data, fp)</code>

To load the JSON file back into the program:

<code class="python">with open('data.json', 'r') as fp:
    data = json.load(fp)</code>

Pickle

Alternatively, use the pickle module to store a dictionary as a pickle file:

<code class="python">import pickle

with open('data.p', 'wb') as fp:
    pickle.dump(data, fp, protocol=pickle.HIGHEST_PROTOCOL)</code>

To restore the dictionary from the pickle file:

<code class="python">with open('data.p', 'rb') as fp:
    data = pickle.load(fp)</code>

Considerations

• JSON: Human-readable, suitable for sharing across different systems and languages.
• Pickle: Binary format, more compact but system-dependent.
• For simple dictionaries, either JSON or Pickle is suitable.
• For complex structured data, both JSON and Pickle provide additional data structures such as lists and dictionaries.
• For more complex data persistence options, consider specialized libraries like SQLAlchemy or MongoDB.

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