Fluentcheck

Fluent assertion framework for Python

Bored of using assert multiple times to check types, intervals, etc. on data passed as input to your Python functions? This generates a lot of boilerplate code.

fluentcheck helps you reducing the lines of code providing a human-friendly and fluent way to make assertions.

Instead of:

def my_function(n, obj):
    assert n is not None
    assert instanceof(n, float)
    assert 0. < n < 1.
    assert obj is not None
    assert isinstance(obj, MyCustomType)

you just streamline the assertions ("checks") you want to make, in a fluent way:

from fluentcheck import Check

def my_function(n, obj):
    Check(n).is_not_None().is_float().is_between(0., 1.)
    Check(obj).is_not_None().is_of_type(MyCustomType)

Fluentcheck can also be used as an assertion framework in tests.

Installation

pip install fluentcheck

or

python setup.py install

Only Python 3 is supported (because you DID update your code to Python3, didn't you?)

Usage

Simply instantiate the Check wrapper around the Python value you want to check out, then fluently append assertions like this:

from fluentcheck import Check

Check(my_value).assertion1().assertion2().assertion3() # and so on

What if an assertion fails? A CheckError is raised: just catch it!

Please notice: if the order of assertions matters to your overall goal,_ then take care of it!_

What can I actually check with it?

To date, here's a list of assertions you can make:

# Numbers
is_none()
is_not_none()
is_number()
is_not_number()
is_integer()
is_not_integer()
is_long()
is_not_long()
is_float()
is_not_float()
is_real()
is_not_real()
is_complex()
is_not_complex()
is_positive()
is_not_positive()
is_negative()
is_not_negative()
is_zero()
is_not_zero()
is_at_least(lower)
is_at_most(upper)
is_between(lower, upper)
is_not_between(lower, upper)

# Sequences
is_empty()
is_not_empty()
is_iterable()
is_not_iterable()
is_couple()
is_triplet()
is_nuple(dimension)
has_dimensionality(dimensionality)

# Tuples
is_tuple()

# Lists
is_list()

# Strings
is_string()
is_not_string()
contains_numbers()
not_contains_numbers()
contains_numbers_only()
contains_chars()
not_contains_chars()
contains_chars_only()
contains_spaces()
not_contains_spaces()
contains_char(_char)
not_contains_char(_char)
is_shorter_than(n_chars)
is_longer_than(n_chars)
has_length(n_chars)
has_not_length(n_chars)
is_lowercase()
is_not_lowercase()
is_uppercase()
is_not_uppercase()
is_camelcase()
is_not_camelcase()
is_snakecase()
is_not_snakecase()
is_unicode()
is_not_unicode()
is_json()
is_not_json()
is_yaml()
is_not_yaml()
is_xml()
is_not_xml()
matches(regex)
not_matches(regex)

# Booleans
is_boolean()
is_not_boolean()
is_true()
is_not_true()
is_truthy()
is_not_truthy()
is_false()
is_not_false()
is_falsy()
is_not_falsy()
has_same_truth_of(val)
has_opposite_truth_of(val)

# Dictionaries
is_dict()
is_not_dict()
has_keys(*args)
has_not_keys(*args)

# Sets
is_set()
is_not_set()
is_subset_of(_set)
is_not_subset_of(_set)
is_superset_of(_set)
is_not_superset_of(_set)
intersects(_set)
not_intersects(_set)

# Functions
is_runnable()
is_not_runnable()

# Modules
is_module()
is_not_module()


# Type hierarchy
is_subtype_of(_type)
is_not_subtype_of(_type)

# Custom types
is_of_type(_type)
is_not_of_type(_type)

# Any type
equals(expected)
not_equals(expected)

# Geographic coords
is_latitude()
is_longitude()
is_azimuth()
is_geopoint()

# UUIDs
is_uuid1()
is_not_uuid1()
is_uuid4()
is_not_uuid4()

Coming soon

The following checks will be added in the upcoming versions:

# Dates
is_date()
is_not_date()
is_datetime()
is_not_datetime()
is_before(_datetime)
is_not_before(_datetime)
is_after(_datetime)
is_not_after(_datetime)
is_today()
is_not_today()
is_yesterday()
is_not_yesterday()
is_tomorrow()
is_not_tomorrow()
is_weekend()
is_not_weekend()
is_this_month()
is_not_this_month()
is_previous_month()
is_not_previous_month()
is_next_month()
is_not_next_month()
is_this_year()
is_not_this_year()
is_last_year()
is_not_last_year()
is_next_year()
is_not_next_year()
is_leap_year()
is_not_leap_year()
is_this_century()
is_not_this_century()
is_before(date)
is_not_before(date)
is_after(date)
is_not_after(date)
is_between_dates(lower, upper)
is_not_between_dates(lower, upper)
is_timezone_aware()
is_not_timezone_aware()
has_timezone(tz)
has_not_timezone(tz)

# Geographic coords
is_plus_code()  # https://plus.codes/
is_not_plus_code()

# Check against a custom rule (lambda)
conforms_to(func)
not_conforms_to(func)

# Sequences
is_sorted(rule=func)
is_not_sorted(rule=func)
is_subsequence_of(subseq)
is_not_subsequence_of(subseq)
has_duplicates()
has_not_duplicates()

# Objects
contains(element)
not_contains(element)
has_attribute(_attr)
has_not_attribute(_attr)

License

MIT license