Iterator class for functional-esque, postfix-chaining programming.
- A single wrapper class exposing chain-able methods for lazily transforming iterators
- Wraps functions from
itertools, and some extras
- Optionally has a length, which is calculated for subsequent operations if possible
Note that this package is for convenience/ interface comfort purposes and does not provide the guarantees of a true functional language.
There may be a significant performance overhead to using deeply nested
FIt instances in tight loops;
see the benchmarks executed by pytest.
from f_it import FIt it = FIt(range(10)) transformed = it.map( # cube elements lambda x: x**3 ).filter( # drop even elements lambda x: x % 2 ).cycle( # repeat the whole iterator 3 times 3 ).islice( # take some elements from the middle 5, 10 ).chain( # add 0-4 to the end range(5) ).chunk( # separate into 2-length chunks 2 ) # __add__ and __radd__ are implemented for chaining other Iterators added = transformed + iter([1, 2, 3]) # nothing has been evaluated yet! # evaluate operations, reading into a list # if tqdm is available, show progress bar as_list = added.progress().to(list)