# Authors:
# Hubert Kario (2016)
#
# See the LICENSE file for legal information regarding use of this file.
"""Helper functions for handling lists"""
from itertools import chain
[docs]
def getFirstMatching(values, matches):
"""
Return the first element in :py:obj:`values` that is also in
:py:obj:`matches`.
Return None if values is None, empty or no element in values is also in
matches.
:type values: collections.abc.Iterable
:param values: list of items to look through, can be None
:type matches: collections.abc.Container
:param matches: list of items to check against
"""
assert matches is not None
if not values:
return None
return next((i for i in values if i in matches), None)
[docs]
def to_str_delimiter(values, delim=", ", last_delim=" or "):
"""
Format the list as a human readable string.
Will format the list as a human readable enumeration, separated by commas
(changable with `delim`) with last value separated with "or" (changable
with `last_delim`).
:type values: collections.abc.Iterable
:param values: list of items to concatenate
:type delim: str
:param delim: primary delimiter for objects, comma by default
:type last_delim: str
:param last_delim: delimiter for last object in list
:rtype: str
"""
# we need to slice the iterator, so we need a copy
values = list(values)
return delim.join(chain((str(i) for i in values[:-2]),
[last_delim.join(str(i) for i in values[-2:])]))