Python itertools

The itertools.cycle function in Python’s itertools module returns an iterator that repeats the items in the given iterable indefinitely. This is useful for cycling through a sequence of items continuously.

The itertools.pairwise function in Python’s itertools module returns an iterator that yields consecutive overlapping pairs of elements from the input iterable. It is useful for processing elements in pairs, such as finding differences or computing rolling statistics.

The itertools.product function in Python’s itertools module returns the Cartesian product of input iterables. It is useful for generating all possible combinations of elements from multiple iterables.

The itertools.combinations function in Python’s itertools module returns an iterator that produces r-length tuples of elements from the input iterable, without regard to the order. It is useful for generating combinations of elements where the order does not matter.

The itertools.permutations function in Python’s itertools module returns successive r-length permutations of elements from the input iterable. This is useful for generating all possible arrangements of a set of elements.

The itertools.tee function in Python’s itertools module returns multiple independent iterators (or "tees") from a single input iterable. It is useful when you need to iterate over the same iterable in parallel, without consuming it.

The itertools.takewhile function in Python’s itertools module returns elements from an iterable as long as the specified predicate function is true. Once the predicate returns false, the iteration stops. This function is useful for extracting a leading sequence from an iterable based on a condition.

The itertools.starmap function in Python’s itertools module returns an iterator that computes the specified function using arguments obtained from the iterable. It is particularly useful for applying a function to the elements of a list of tuples or other iterables where the elements themselves are iterables.

The itertools.islice function in Python’s itertools module returns an iterator that produces selected elements from the input iterable. It is useful for slicing iterables in a memory-efficient way.

The itertools.groupby function in Python’s itertools module returns consecutive keys and groups from the input iterable. The elements are grouped based on the value of a specified key function. It is useful for grouping elements in an iterable that share a common property.

The itertools.filterfalse function in Python’s itertools module returns an iterator that filters elements from an iterable, returning only those for which a specified function returns false. It is useful for excluding elements based on a condition.

The itertools.compress function in Python’s itertools module filters elements from an iterable based on the values of a selector iterable. It is useful for selecting elements from one iterable when the corresponding elements in another iterable are true.

The itertools.chain function in Python’s itertools module returns an iterator that iterates over multiple iterables in sequence, as if they were a single iterable. It is useful for chaining together multiple sequences to be treated as one continuous sequence.

The itertools.accumulate function in Python’s itertools module returns an iterator that yields accumulated sums, or accumulated results of other binary functions, specified via the func parameter. It is useful for performing cumulative operations on iterable data.

The itertools.repeat function in Python’s itertools module returns an iterator that repeats a single value infinitely or a specified number of times. It is useful for generating constant sequences or combining with other iterators.

The itertools.cycle function in Python’s itertools module returns an iterator that repeats the items in the given iterable indefinitely. This is useful for cycling through a sequence of items continuously.

The itertools.count function in Python’s itertools module returns an iterator that generates consecutive integers, starting from a specified number. It is often used for looping over a sequence of numbers in an efficient way.