codekingpro/portable-devtools

1import collections.abc2import functools3 4 5# from jaraco.functools 3.56def pass_none(func):7    """8    Wrap func so it's not called if its first param is None9 10    >>> print_text = pass_none(print)11    >>> print_text('text')12    text13    >>> print_text(None)14    """15 16    @functools.wraps(func)17    def wrapper(param, *args, **kwargs):18        if param is not None:19            return func(param, *args, **kwargs)20 21    return wrapper22 23 24# from jaraco.functools 4.025@functools.singledispatch26def _splat_inner(args, func):27    """Splat args to func."""28    return func(*args)29 30 31@_splat_inner.register32def _(args: collections.abc.Mapping, func):33    """Splat kargs to func as kwargs."""34    return func(**args)35 36 37def splat(func):38    """39    Wrap func to expect its parameters to be passed positionally in a tuple.40 41    Has a similar effect to that of ``itertools.starmap`` over42    simple ``map``.43 44    >>> import itertools, operator45    >>> pairs = [(-1, 1), (0, 2)]46    >>> _ = tuple(itertools.starmap(print, pairs))47    -1 148    0 249    >>> _ = tuple(map(splat(print), pairs))50    -1 151    0 252 53    The approach generalizes to other iterators that don't have a "star"54    equivalent, such as a "starfilter".55 56    >>> list(filter(splat(operator.add), pairs))57    [(0, 2)]58 59    Splat also accepts a mapping argument.60 61    >>> def is_nice(msg, code):62    ...     return "smile" in msg or code == 063    >>> msgs = [64    ...     dict(msg='smile!', code=20),65    ...     dict(msg='error :(', code=1),66    ...     dict(msg='unknown', code=0),67    ... ]68    >>> for msg in filter(splat(is_nice), msgs):69    ...     print(msg)70    {'msg': 'smile!', 'code': 20}71    {'msg': 'unknown', 'code': 0}72    """73    return functools.wraps(func)(functools.partial(_splat_inner, func=func))74