cornsnake.util_list

  1"""
  2Functions for manipulating lists of data. Functions include chunking lists, excluding elements from one list that are present in another, finding the intersection of two lists, and various other list operations.
  3
  4[Documentation](http://docs.mrseanryan.cornsnake.s3-website-eu-west-1.amazonaws.com/cornsnake/util_list.html)
  5"""
  6
  7from typing import Generator
  8import typing
  9
 10
 11def chunk(
 12    list_a: list, CHUNK_SIZE: int, min_chunk_size: int = 1
 13) -> Generator[list, None, None]:
 14    """
 15    Function to chunk a list into sublists of size n.
 16
 17    Args:
 18    list_a (list): The input list to be chunked.
 19    n (int): The size of each chunk.
 20    min_chunk_size: The minimum size for a chunk. Set to avoid a smaller chunk at the end, instead add its contents to the penultimate chunk.
 21
 22    Yields:
 23    list: Sublists of size n.
 24    """
 25
 26    if min_chunk_size > CHUNK_SIZE:
 27        raise ValueError(
 28            f"min_chunk_size {min_chunk_size} is greater than CHUNK_SIZE {CHUNK_SIZE}"
 29        )
 30
 31    for i in range(0, len(list_a), CHUNK_SIZE):
 32        list_end = i + CHUNK_SIZE
 33        if len(list_a) - list_end < min_chunk_size:
 34            list_end = len(list_a)
 35            yield list_a[i:list_end]
 36            break
 37
 38        yield list_a[i:list_end]
 39
 40
 41def excluding(list1: list, list2: list) -> list:
 42    """
 43    Function to exclude elements from list1 that are present in list2.
 44
 45    Args:
 46    list1 (list): The main list.
 47    list2 (list): The list of elements to exclude.
 48
 49    Returns:
 50    list: List1 with elements excluded.
 51    """
 52    return [x for x in list1 if x not in list2]
 53
 54
 55def intersecting(list1: list, list2: list) -> list:
 56    """
 57    Function to find the intersection of two lists.
 58
 59    Args:
 60    list1 (list): The first list.
 61    list2 (list): The second list.
 62
 63    Returns:
 64    list: Intersection of list1 and list2.
 65    """
 66    return [value for value in list1 if value in list2]
 67
 68
 69def first_or_none(my_list: list) -> typing.Any | None:
 70    """Function to return the first element of a list or None if the list is empty."""
 71    if len(my_list) > 0:
 72        return my_list[0]
 73    return None
 74
 75
 76def flatten(my_list: list) -> list:
 77    """Function to flatten a list of lists into a single list."""
 78    return [item for sublist in my_list for item in sublist]
 79
 80
 81def list_with_first_or_empty(my_list: list) -> list:
 82    """Function to return a list containing the first element of the input list, or an empty list if the input list is empty."""
 83    first_or_none_value = first_or_none(my_list)
 84    if first_or_none_value is None:
 85        return []
 86    return [first_or_none_value]
 87
 88
 89def not_none(my_list: list) -> list:
 90    """Function to return a list with non-None elements."""
 91    return list(filter(lambda f: (f is not None), my_list))
 92
 93
 94def not_none_and_unique(my_list: list) -> list:
 95    """Function to return a list with unique non-None elements."""
 96    return list(set(filter(lambda f: (f is not None), my_list)))
 97
 98
 99def remove_empty_strings(list_of_strings: list[str]) -> list[str]:
100    """Function to remove empty strings from a list of strings."""
101    parts_filtered = []
102    for part in list_of_strings:
103        if part and len(part) > 0:
104            parts_filtered.append(part)
105    return parts_filtered
106
107
108def strip_strings(list_of_strings: list[str]) -> list[str]:
109    """Function to strip leading and trailing whitespace from strings in a list."""
110    parts_stripped = []
111    for part in list_of_strings:
112        parts_stripped.append(part.strip())
113    return parts_stripped
114
115
116def unique(my_list: list) -> list:
117    """Function to return a list with unique elements from the input list."""
118    return list(set(my_list))