Predicates

`identity`(x)	Returns its argument as it is.
`equals`(a[, b])	if only `a` is passed, a function is returned that returns True when the `arg` passed to it is equal to `a`; else returns True when `a`,``b`` and `*args` are equal.
`is_`(a[, b])	if only `a` is passed, a function is returned that returns True when the `arg` passed is the same object as `a` ; else returns True when `a`,``b`` and `*args` are.
`less_than`(a[, b])	if only `a` is passed, a function is returned that returns True when the `arg` passed to is less than `a`; else returns True when `a` is less than``b`` and `*args`.
`greater_than`(a[, b])	if only `a` is passed, a function is returned that returns True when the `arg` passed to is greater than `a`; else returns True when `a` is greater than``b`` and `*args`.
`less_than_eq`(a[, b])	if only `a` is passed, a function is returned that returns True when the `arg` less than or equal to `a`; else returns True when `a` is less than or equal to `b` and `*args`.
`greater_than_eq`(a[, b])	if only `a` is passed, a function is returned that returns True when the `arg` greater than or equal to `a`; else returns True when `a` is greater than or equal to `b` and `*args`.
`complement`(expr)	Takes in a predicate or a Boolean expression and returns a negated version of the predicate or expression.
`is_even`(num)	Returns true when num is even.
`is_odd`(num)	Returns true when num is odd
`is_divisible`(divident, divisor)	Returns true if dividend is divisible by divisor.
`is_divisible_by`(divisor)	Takes a `divisor` And returns a function (closure) That expects a dividend.
`is_numeric`(entity)	Return True if `entity` Is an `int`, `float`, or a `complex`.
`is_atom`(entity)	Everything that is NOT an iterable(except strings) are considered atoms.
`contains`(entity, collection)	Checks whether collection contains the given entity.
`is_empty`(collection)	Returns true if the collection is empty.
`is_nested`(collection)	returns true if a collection is nested.
`all_predicates`(*predicates)	Takes a set of predicates and returns a function that takes an entity and checks if it satisfies all the predicates.
`some_predicates`(*predicates)	Takes a set of predicates and returns a function that takes an entity and checks if it satisfies some of the predicates.

functionali.identity(x): Returns its argument as it is.

functionali.equals(a, b=None, *args)

if only a is passed, a function is returned that returns True when the arg passed to it is equal to a; else returns True when a,``b`` and *args are equal.

with one argument

>>> equals_one = equals(1)
>>> equals_one(1)
True
>>> equals_one(2)
False

with two or more arguments

>>> equals(1,1,1)
True
>>> equals(1,1,2)
False

Added in version: 0.1.0

functionali.is_(a, b=None, *args)

if only a is passed, a function is returned that returns True when the arg passed is the same object as a ; else returns True when a,``b`` and *args are.

with one argument

>>> d1 = {1,2,3}
>>> d2 = {1,2,3}
>>> is_d1 = is_(d1)
>>> is_d1(d2)
>>> False
>>> d1 == d2
>>> True

with two or more arguments

>>> is_(d1,d1)
>>> True
>>> is_(d1,d1,d2)
>>> False

Added in version: 0.1.0

functionali.less_than(a, b=None, *args)

if only a is passed, a function is returned that returns True when the arg passed to is less than a; else returns True when a is less than``b`` and *args.

with one argument

>>> less_than_one = less_than(1)
>>> less_than_one(2)
False
>>> less_than_one(0)
True

with two or more arguments

>>> less_than(1,2)
>>> True
>>> less_than(1,2,3)
True
>>> less_than(1,2,3,1)
False

Useful to use with filter

>>> list(filter(less_than(5),range(10)))
[0,1,2,3,4]

Added in version: 0.1.0

functionali.greater_than(a, b=None, *args)

if only a is passed, a function is returned that returns True when the arg passed to is greater than a; else returns True when a is greater than``b`` and *args.

with one argument

>>> greater_than_one = greater_than(1)
>>> greater_than_one(2)
True
>>> greater_than_one(0)
False

with two or more arguments

>>> greater_than(2,1)
>>> True
>>> greater_than(3,2,1)
True
>>> greater_than(3,2,1,3)
False

Useful to use with filter

>>> list(filter(greater_than(5),range(10)))
[6,7,8,9]

Added in version: 0.1.0

functionali.less_than_eq(a, b=None, *args)

if only a is passed, a function is returned that returns True when the arg less than or equal to a; else returns True when a is less than or equal to b and *args.

with one argument

>>> less_than_or_eq_to_one = less_than_eq(1)
>>> less_than_or_eq_to_one(2)
False
>>> less_than_or_eq_to_one(1)
True

with two or more arguments

>>> less_than_eq(1,2)
>>> True
>>> less_than_eq(1,2,3)
True
>>> less_than_eq(1,2,3,1)
True

Useful to use with filter

>>> list(filter(less_than_eq(5),range(10)))
[0,1,2,3,4,5]

Added in version: 0.1.0

functionali.greater_than_eq(a, b=None, *args)

if only a is passed, a function is returned that returns True when the arg greater than or equal to a; else returns True when a is greater than or equal to b and *args.

with one argument

>>> greater_than_eq_one = greater_than_eq(1)
>>> greater_than_eq_one(2)
True
>>> greater_than_eq_one(1)
True

with two or more arguments

>>> greater_than_eq(2,1)
>>> True
>>> greater_than_eq(3,2,1)
True
>>> greater_than_eq(3,2,1,3)
True

Useful to use with filter

>>> list(filter(greater_than_eq(5),range(10)))
[5,6,7,8,9]

Added in version: 0.1.0

functionali.complement(expr: Union[bool, Callable[[Any], bool]]) → Union[bool, Callable[[Any], bool]]

Takes in a predicate or a Boolean expression and returns a negated version of the predicate or expression.

>>> complement(True)
>>> False

>>> def fn(el): # returns the Boolean of el
    return bool(el)
>>> negated_fn = complement(fn)
>>> fn(1)
>>> True
>>> negated_fn(1)
>>> False

Added in version: 0.1.0

functionali.is_even(num: int) → bool

Returns true when num is even.

Added in version: 0.1.0

functionali.is_odd(num: int) → bool

Returns true when num is odd

Added in version: 0.1.0

functionali.is_divisible(divident: Union[int, float], divisor: Union[int, float]) → bool

Returns true if dividend is divisible by divisor.

Added in version: 0.1.0

functionali.is_divisible_by(divisor: Union[int, float]) → Callable[[Union[int, float]], bool]

Takes a divisor And returns a function (closure) That expects a dividend. returns true if it passes the divisibility test. for e.g.

>>> f = is_divisible_by(5)
>>> f(10)
True
>>> f(7)
False

This is particularly useful to use with a filter.

>>> list(filter(is_divisible_by(5), [1,2,3,4,5,6,7,8,9,10]))
[5, 10]

Suppose you want to filter out numbers that are divisible by 2 or 3

>>> list(filter(some_predicates([is_divisible_by(2), is_divisible_by(3)]), range(1, 10)))
[2, 3, 4, 6, 8, 9, 10]

Added in version: 0.1.0

functionali.is_numeric(entity: Any) → bool

Return True if entity Is an int, float, or a complex.

Added in version: 0.1.0

functionali.is_atom(entity: Any) → bool

Everything that is NOT an iterable(except strings) are considered atoms.

>>> is_atom("plain string")
    True
>>> is_atom(1)
    True
>>> is_atom([1, 2])
    False

Added in version: 0.1.0

functionali.contains(entity: Any, collection: Iterable) → bool

Checks whether collection contains the given entity. Note, won’t automatically convert a tuple of keys and values to a dict.

Added in version: 0.1.0

functionali.is_empty(collection: Iterable) → bool

Returns true if the collection is empty.

Added in version: 0.1.0

functionali.is_nested(collection: Iterable) → bool: returns true if a collection is nested. Added in version: 0.1.0

functionali.all_predicates(*predicates: Callable[[Any], bool]) → Callable[[Any], bool]

Takes a set of predicates and returns a function that takes an entity and checks if it satisfies all the predicates.

>>> even_and_prime = all_predicates(is_even, is_prime)
>>> even_and_prime(2)
True
>>> even_and_prime(4)
False
>>> even_and_prime(3)
False

Added in version: 0.1.0

functionali.some_predicates(*predicates: Callable[[Any], bool]) → Callable[[Any], bool]

Takes a set of predicates and returns a function that takes an entity and checks if it satisfies some of the predicates.

>>> even_or_prime = some_predicates(is_even, is_prime)
>>> even_or_prime(2)
True
>>> even_and_prime(4)
True
>>> even_and_prime(3)
True

Added in version: 0.1.0