unbuiltins

Thoroughly tested and MyPy compatible constants and functions you'd expect to find in the Python builtins.

Install

requires python 3.8 or higher

pip install unbuiltins

Usage

from unbuiltins import *

Missing

Like the constant None, Missing can be used for e.g. optional function arguments:

def say(value: Missable[str] = Missing):
    if value is Missing:
        print('*silence*')
    else:
        print(value)

frozendict

The builtins include frozenset, but frozendict is nowhere to be found (see PEP 416).

frozendict is basically an immutable and hashable dict:

assert frozendict(spam='spam') == dict(spam='spam')
assert {frozendict(): 'empty'}[frozendict()] == 'empty'

It accepts generic type arguments and supports the merge (|) operator, like dict since Python 3.9:

def add_eggs(value: frozendict[str, str]) -> frozendict[str, Union[str, int]]: 
    return value | dict(eggs=6)

assert 'eggs' in add_eggs(frozendict(spam='spam')) 

first

Behaves identical to next, but works for all iterables:

assert first([42, 666, 69]) == 42
assert first([], default='empty') == 'empty'
assert first(iter(dict(eggs=6))) == 'eggs'

filternone

Return those items of iterable that are not None:

assert list(filternone(['', None, 0, False])) == ['', 0, False]

either

Returns the first argument that is not None or Missing:

assert either(None, None, False) is False