Posts

Intro In this post, we will look at the contextmanager function from the contextlib module. The contextlib.contextmanager function is used as a decorator that allows you to create context managers using a generator function instead of writing a class with __enter__ and __exit__ methods. It’s a cleaner, more pythonic way to handle resource management, setup/teardown operations, and temporary state changes. Context managers in a nutshell You might have come across code like: ...

Intro In this post, we will look at the groupby function from the itertools module. The itertools.groupby function groups consecutive elements from an iterable. It accepts an iterable and an optional callable key that computes a key value for each element. It returns an iterator that yields tuples of (key, group), where group itself is an iterator over the consecutive elements that share that key value. If key is not specified or passed as None, then the value of each element is used as key value. ...

Intro In this post, we will look at the defaultdict datatype from the collections module. The collections.defaultdict is a subclass of the built-in dict that accepts a callable (default_factory) during its initialization. Then, when you try to access a key in the initialized object, it does a regular dict lookup to fetch the key’s value. If the key is missing, it calls the default_factory that generates a value for the key requested. This key-value pair is then stored in the dict and the value is returned. ...

Intro In this post, we will look at the partial function in the functools module. The functools.partial function accepts a callable, with arguments (positional and keyword), and returns a partial object that has not yet executed the callable. When this partial object is called, it then passes the arguments to the callable and returns the output. The idea is to have an object that can store even some of the arguments required by the callable, such that it can be executed in the future. Think of it like taking the callable, with any arguments that you can pass, and then freezing it for a later point. ...