python / expert
Snippet
Advanced Pattern Matching with Guards
Structural Pattern Matching (introduced in Python 3.10) allows for expressive data deconstruction. Using 'guards' (the 'if' clause after a pattern) enables adding conditional logic directly into the matching process, allowing for more granular control over complex dictionary or object structures.
snippet.py
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def process_data(payload):match payload:case {"type": "user", "id": int(uid)} if uid > 1000:return f"Admin logic for {uid}"case {"type": "user", "id": int(uid)}:return f"User logic for {uid}"case _:raise ValueError("Unknown format")
Breakdown
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match payload:
Starts the pattern matching block against the payload variable.
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case {"type": "user", "id": int(uid)} if uid > 1000:
Matches a dict structure, captures 'uid', and applies a conditional guard.
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case _:
The wildcard pattern that matches anything not caught by previous cases.