Quick recall
Methods like `__iter__`, `__next__`, `__call__`, `__eq__`, `__lt__`, and `__hash__` define how custom objects participate in loops, comparisons, hashing, and callable syntax.
JSON is portable text, Pickle is Python-specific object serialization, and CSV is a simple tabular interchange format.
Lists are mutable ordered sequences that support indexing, slicing, appending, extending, and in-place updates.
Lists are mutable dynamic arrays; tuples are immutable ordered records.
Logging beats `print` for real systems because it supports levels, structured routing, timestamps, and configurable destinations.
`break` stops a loop, `continue` skips to the next iteration, `pass` is a placeholder, and loop `else` runs only if the loop did not break.
Python resolves imports through its module search path, and you can import names directly or alias modules for readability.
Python's advanced model includes MRO, metaclasses, descriptors, duck typing, and the EAFP vs LBYL style trade-off.
Mutable objects can change in place; immutable objects require a new object for a changed value.
Nested dictionaries represent hierarchical data, and helper methods like `get`, `setdefault`, and `update` make access and merging cleaner.
Nested lists make shallow copies especially important because the outer list may copy while inner lists still alias the same objects.
Python lets you control how callers pass arguments so APIs can be both flexible and explicit.