More Itertools

import more_itertools

from more_itertools import chunked, windowed, peekable, take, unique_everseen

from more_itertools import chunked, windowed, peekable, take, first

# Break data into chunks
data = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
chunks = list(chunked(data, 3))
print(chunks)  # [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10]]

# Create sliding windows
windows = list(windowed(data, 3))
print(windows)  # [(1, 2, 3), (2, 3, 4), (3, 4, 5), ...]

# Peek ahead in an iterator
p = peekable(iter(data))
print(p.peek())  # 1 (without consuming)
print(next(p))   # 1 (now consumed)

# Take first n items
first_five = take(5, data)
print(first_five)  # [1, 2, 3, 4, 5]

# Get first item safely
print(first(data))        # 1
print(first([], 'none'))  # 'none'

def chunked(iterable, n, strict=False):
    """Break iterable into lists of length n"""

def batched(iterable, n, *, strict=False):
    """Group items into batches of size n"""

def grouper(iterable, n, incomplete='fill', fillvalue=None):
    """Group into fixed-length chunks with fillvalue"""

def partition(pred, iterable):
    """Partition into false and true groups"""

def windowed(iterable, n, fillvalue=None, step=1):
    """Create sliding window of size n"""

def pairwise(iterable):
    """Return successive overlapping pairs"""

def stagger(iterable, offsets=(0, 1), longest=False, fillvalue=None):
    """Create lagged iterables"""

class peekable:
    """Iterator that allows peeking ahead"""
    def peek(self, default=None): ...
    def prepend(self, *values): ...

class seekable:
    """Iterator that allows seeking to positions"""
    def seek(self, index): ...
    def relative_seek(self, count): ...

def spy(iterable, n=1):
    """Return first n items and iterator"""

def take(n, iterable):
    """Return first n items as list"""

def first(iterable, default=None):
    """Return first item or default"""

def nth(iterable, n, default=None):
    """Return nth item or default"""

def filter_except(function, iterable, *exceptions):
    """Filter with exception handling"""

def interleave(*iterables):
    """Round-robin interleaving"""

def zip_equal(*iterables):
    """Zip ensuring equal lengths"""

def intersperse(element, iterable):
    """Insert element between items"""

def prepend(value, iterator):
    """Prepend value to iterator"""

def dotproduct(vec1, vec2):
    """Compute dot product"""

def convolve(signal, kernel):
    """Compute convolution"""

def polynomial_eval(coefficients, x):
    """Evaluate polynomial at x"""

def sum_of_squares(iterable):
    """Sum the squares of items"""

def nth_prime(n, *, approximate=False):
    """Return nth prime number (0-indexed)"""

def powerset(iterable):
    """Generate powerset of items"""

def distinct_combinations(iterable, r):
    """Combinations of distinct items"""

def partitions(n):
    """Integer partitions of n"""

def circular_shifts(iterable):
    """All circular shifts"""

def unique_everseen(iterable, key=None):
    """Unique items preserving order"""

def duplicates_everseen(iterable, key=None):
    """Duplicate items preserving order"""

def all_unique(iterable, key=None):
    """Check if all items unique"""

def ilen(iterable):
    """Length of iterable"""

def quantify(iterable, pred=bool):
    """Count matching items"""

def minmax(iterable, *, default=None, key=None):
    """Find min and max in single pass"""

def all_equal(iterable):
    """Check if all elements equal"""

def always_iterable(obj, base_type=(str, bytes)):
    """Ensure input is iterable"""

def is_sorted(iterable, *, key=None, reverse=False, strict=False):
    """Check if sequence is sorted"""

def mark_ends(iterable):
    """Mark first and last elements"""

def sort_together(iterables, *, key_list=None, reverse=False):
    """Sort multiple sequences together"""

def combination_index(element, pool):
    """Get index of combination"""

def nth_combination(iterable, r, index):
    """Get combination at index"""

def permutation_index(element, pool):
    """Get index of permutation"""

def iter_index(iterable, value, *, start=0, stop=None):
    """Find all indices of value"""

def random_product(*iterables, repeat=1):
    """Random Cartesian product element"""

def random_combination(iterable, r):
    """Random combination"""

def sample(iterable, k, *, counts=None):
    """Sample k elements"""

def iterate(func, value):
    """Generate sequence by applying function"""

def tabulate(func, start=0):
    """Tabulate function results"""

def iter_except(func, exception, first=None):
    """Iterate until exception"""

class countable:
    """Iterator wrapper that tracks items seen"""
    def items_seen(self): ...

def consumer(func):
    """Decorator for coroutine consumers"""

def raise_(exception):
    """Utility for raising exceptions in expressions"""

def iequals(*iterables):
    """Test if iterables produce same elements"""

def difference(iterable, *others):
    """Elements in first not in others"""

def before_and_after(predicate, iterable):
    """Split at first matching element"""

def flatten(iterable):
    """Flatten one level of nesting"""

def collapse(iterable, base_type=None, levels=None):
    """Deep flattening of nested structures"""

def map_reduce(iterable, keyfunc, valuefunc=None, reducefunc=None):
    """Map-reduce operation"""

class time_limited:
    """Time-limited iteration class"""

def interleave_randomly(*iterables):
    """Randomly interleave multiple iterables"""

def takewhile_inclusive(predicate, iterable):
    """Takewhile including first failing element"""

def with_iter(context_manager):
    """Context-managed iteration"""

def iter_suppress(iterable, *exceptions):
    """Exception suppression during iteration"""

from collections.abc import Iterable, Iterator
from typing import TypeVar, Any, Callable, Optional

T = TypeVar('T')
U = TypeVar('U')

class UnequalIterablesError(ValueError):
    """Raised when iterables have unequal lengths"""

class SequenceView:
    """Provides view into sequence with lazy slicing"""
    def __init__(self, target): ...
    def __getitem__(self, index): ...
    def __len__(self): ...

class bucket:
    """Dynamic bucketing of iterable items by key function"""
    def __init__(self, iterable, key, validator=None): ...
    def __contains__(self, value): ...
    def __getitem__(self, value): ...

class callback_iter:
    """Convert callback-based function to iterator"""
    def __init__(self, func, callback_kwd='callback', wait_seconds=0.1): ...
    def __enter__(self): ...
    def __exit__(self, exc_type, exc_value, traceback): ...

class run_length:
    """Run-length encoding and decoding operations"""
    @staticmethod
    def encode(iterable): ...
    @staticmethod
    def decode(iterable): ...

class islice_extended:
    """Extended islice with negative index support"""
    def __init__(self, iterable, *args): ...
    def __getitem__(self, key): ...

class numeric_range:
    """Extended range() for any numeric types"""
    def __init__(self, *args): ...
    def __contains__(self, value): ...