List Functions

filter

filter(input_list, fn, tolerate_errors=false)

Filter a list based on whether a refiner function outputs

true or false for each value.



Args:

    input_list (list): list or list json-encoded as a string

    fn (str): name of function to be used for mapping.

    tolerate_errors (bool): should errors be allowed (with elements causing errors filtered out)?



Returns:

    Returns a list of the filtered elements



Examples:

    filter([' a', ' b '], 'contains(x, \'a\')') -> [' a']

first

first(input_list)

Returns the first element of the list



Args:

    input_list (list): the list containing values



Returns:

    The first element, or an error if it doesn't exist



Examples:

    first(['a', 'b', 'c']) -> 'a'

first_or_default

first_or_default(input_list, default)

Returns the first element of the list, or the default value

if the list is empty



Args:

    input_list (list): the list containing values

    default (any): the default value to use if list is empty



Returns:

    The first element, or default if the list is empty



Examples:

    first_or_default(['a', 'b', 'c'], 'd') -> 'a'

    first_or_default([], 'd') -> 'd'

flatten_list

flatten_list(nested_list)

Turn a nested list into a single list of all the elements which were

previously within its separate lists



Args:

    nested_list (list): nested list



Returns:

    Returns a flattened list containing all of the elements in the list inputs



Examples:

    flatten_list([['a', 'b'], ['c']]) -> ['a', 'b', 'c']

last

last(input_list)

Returns the last element of the list



Args:

    l (list): the list containing values



Returns:

    The last element, or an error if it doesn't exist



Examples:

    last(['a', 'b', 'c']) -> 'c'

last_or_default

last_or_default(input_list, default)

Returns the last element of the list, or the default value

if the list is empty



Args:

    input_list (list): the list containing values

    default (any): the default value to use if list is empty



Returns:

    The last element, or default if the list is empty



Examples:

    last_or_default(['a', 'b', 'c'], 'd') -> 'c'

    last_or_default([], 'd') -> 'd'

list

list(*args: Any)

Creates a list from all the arguments



Args:

    args (list): Variable length arguments



Returns:

    Returns a list



Examples:

    list('a', 'b', 'c') -> ['a', 'b', 'c']

list_get

list_get(input_list, n, default=None)

Returns n-th element of the list



Args:

    input_list (list): the list containing values

    n (int): the zero-indexed index to be returned

    default (any): the default value to return if there is no nth index. Defaults to None



Returns:

    Returns n-th element of the list, or default if it doesn't exist



Examples:

    list_get(['a', 'b', 'c'], 0) -> 'a'

list_get_range

list_get_range(input_list, rng)

Returns a range of elements from a list



Args:

    l (list): the list containing values

    rng (str): a range of list items to return, represented as a python array range



Returns:

    Returns the list of elements in the specified range



Examples:

    list_get_range(['a', 'b', 'c'], '1:2') -> ['b']

    list_get_range(['a', 'b', 'c'], '1:') -> ['b', 'c']

    list_get_range(['a', 'b', 'c'], '-1:') -> ['c']

    list_get_range(['a', 'b', 'c'], '100:') -> []

map

map(input_list, fn, tolerate_errors=false)

Operate on a list by transforming each element using a refiner function



Args:

    input_list (list): list of element to be operated on. Can also be a string which decodes to a json list

    fn (str): name of function to be used for mapping

    tolerate_errors (bool): should errors be allowed (elements throwing errors are filtered out)



Returns:

    Returns a list of the mapped elements



Examples:

    map([' a', ' b '], 'contains(x, \'a\')') -> [True, False]

    map([' a', ' b '], 'echo(\'1\', x, \'2\')') -> ['1 a2', '1 b 2']

merge_lists

merge_lists(*args: Any)

Merges several lists into a single list



Args:

    args (str): Variable length arguments: the lists to merge



Returns:

    a single list



Examples:

    merge_lists(['a', 'b'], ['c']) -> ['a', 'b', 'c']