Search results
Results From The WOW.Com Content Network
Introduced in Python 2.2 as an optional feature and finalized in version 2.3, generators are Python's mechanism for lazy evaluation of a function that would otherwise return a space-prohibitive or computationally intensive list. This is an example to lazily generate the prime numbers:
Since 7 October 2024, Python 3.13 is the latest stable release, and it and, for few more months, 3.12 are the only releases with active support including for bug fixes (as opposed to just for security) and Python 3.9, [55] is the oldest supported version of Python (albeit in the 'security support' phase), due to Python 3.8 reaching end-of-life.
For example, reverse :: List a -> List a, which reverses a list, is a natural transformation, as is flattenInorder :: Tree a -> List a, which flattens a tree from left to right, and even sortBy :: (a -> a -> Bool) -> List a -> List a, which sorts a list based on a provided comparison function.
Folds can be regarded as consistently replacing the structural components of a data structure with functions and values. Lists, for example, are built up in many functional languages from two primitives: any list is either an empty list, commonly called nil ([]), or is constructed by prefixing an element in front of another list, creating what is called a cons node ( Cons(X1,Cons(X2,Cons ...
(The previous statement applies to Python 3.x. In Python 2.x, the next() method is equivalent.) A StopIteration exception will be raised when no more elements are left. The following example shows an equivalent iteration over a sequence using explicit iterators:
In languages with single dispatch, classes typically also include method definitions. In languages with multiple dispatch, methods are defined by generic functions. There are exceptions where single dispatch methods are generic functions (e.g. Bigloo's object system).
In Python 3, filter was changed to return an iterator rather than a list. [13] The complementary functionality, returning an iterator over elements for which the predicate is false, is also available in the standard library as filterfalse in the itertools module.
3 Python implementation. 4 Hashing trick. 5 See also. ... The bag-of-words model is commonly used in methods of document classification where, for example, ...