Python Dictionaries for Handling Exchange Price Data

Summary

The document introduces Python dictionaries through a sample exchange response containing a trading symbol and its latest price. It explains key-value storage, unique keys, mutable contents, and how dictionaries differ from indexed sequences. The example illustrates why an API response can be handled as a dictionary, though it does not discuss trading decisions or analyze the quoted market price.

It surveys common operations: creating dictionaries, adding or updating entries, removing entries, retrieving values and keys, iterating over key-value pairs, checking membership, and counting entries. It contrasts direct lookup, which raises an error for a missing key, with a lookup method that returns no value. Examples are instructional snippets rather than a tested trading workflow, and the material does not cover API error handling, data validation, or how to use prices in a strategy.

Key ideas

• A dictionary stores data as key-value pairs and uses keys for lookup.
• Keys must be unique and immutable, while values can have varied types.
• Dictionaries can be modified by adding, updating, or deleting entries.
• Lookup methods differ in how they handle missing keys.
• Iteration, membership checks, and length queries support routine dictionary inspection.

Tags

From a private course collection; the original is not published.