Advanced Python Features You May Not Know

Cleaning String Input

Cleaning user input is relevant to almost every program; converting characters to lower‑ or upper‑case often suffices, but for more complex cases you can replace whitespace characters ("\n", "\t") with a single space and remove "\r", or use the unicodedata package with its combining() function to strip all accents.

Slicing Iterators

Attempting to slice a generator raises a TypeError because generators are not subscriptable. The simple solution is to use itertools.islice , which creates an iterator that yields the desired slice while consuming all items up to the start point.

Skipping the Beginning of an Iterable

When a file starts with an unwanted variable number of lines (e.g., comments), itertools provides an easy way to drop those initial items without knowing their count, allowing you to process only the relevant part of the iterable.

Functions with Only Keyword Arguments (kwargs)

Defining functions that accept only keyword arguments improves clarity; this is achieved by placing a solitary * before the keyword parameters. Positional arguments placed before the * remain valid.

Creating Objects that Support the with Statement

Custom context managers can be built by implementing __enter__ and __exit__ methods, or more concisely using the contextlib.contextmanager decorator, which turns a generator into a proper with‑statement manager.

Using __slots__ to Save Memory

When many instances of a class are created, memory usage can balloon because each instance stores its attributes in a dictionary. Declaring __slots__ replaces the per‑instance dict with a fixed‑size array, dramatically reducing memory consumption, though it disallows adding new attributes and prevents multiple inheritance.

Limiting CPU and Memory Usage

The resource module lets you set soft and hard limits for CPU time (RLIMIT_CPU) and memory (RLIMIT_AS). After setting the limits, a signal handler can terminate the program if the CPU time exceeds the bound.

Controlling What Can Be Imported

Unlike languages such as Go, Python exports everything by default. By defining an __all__ list you can explicitly specify which names are public; an empty __all__ makes the module export nothing, causing AttributeError on import.

Simplified Implementation of Comparison Operators

Implementing all rich comparison methods ( __lt__ , __le__ , __gt__ , __ge__ ) is tedious. The functools.total_ordering decorator requires only __lt__ and __eq__ , automatically providing the remaining methods.

Conclusion

Not every feature described is essential for daily Python work, but many can simplify otherwise verbose tasks. All of these utilities belong to the Python standard library, so you should first search there before turning to third‑party packages.