Python Runtime — Middle¶

Write with CPython’s practical behavior in mind, while keeping correctness independent of implementation details.

• Names reference objects; assignment usually does not copy.
• Prefer iterators and generators for large streams.
• Understand shallow versus deep copies before mutating nested data.
• Use with for files, locks, and resources.
• Measure memory or CPU with a profiler; do not infer it from syntax.

Use tracemalloc for allocation investigations and cProfile for CPU hotspots. Optimize only after a representative measurement.