Immutable struct with sane defaults
Immutable struct built on top of collections.namedtuple with sane defaults
Immutable, dictionary-like data structure (Note: istruct is not an immutable version of the existing struct in Python)
Support required and optional fields (with default values)
Strictly disallow positional arguments
pip install istruct
First, create an istruct object called person where first_name and last_name are required whereas middle_name, dob and email are optional (with default values specified).
>>> from istruct import istruct >>> person = istruct("first_name", "last_name", middle_name="", dob="2000-01-01", email=None)
Then, create an instance of person with first_name, last_name and middle_name.
>>> p = person(first_name="Jim", last_name="Raynor", middle_name="Eugene") >>> p istruct(first_name='Jim', last_name='Raynor', email=None, dob='2000-01-01', middle_name='Eugene')
You can retrieve field values like you would normally do.
>>> p.first_name 'Jim' >>> p.dob '2000-01-01'
p is immutable, meaning that it cannot be modified after created. Thus, set/delete operations like below would fail, raising an AttributeError.
>>> p.first_name = "James" Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: can't set attribute >>> del p.email Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: can't delete attribute
istruct only accepts named/keyword arguments. It strictly disallows positional arguments by design.
>>> p = person("Jim", "Raynor") Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/Users/microamp/src/microamp/istruct/istruct/__init__.py", line 52, in _istruct "(%d found)" % (len(positional),)) TypeError: No positional arguments are allowed in istruct (2 found)
istruct would raise a TypeError when one or more required fields are omitted.
>>> p = person(last_name="Raynor") Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/Users/microamp/src/microamp/istruct/istruct/__init__.py", line 56, in _istruct return nt(**merge_dicts(kwargs, attrs)) TypeError: __new__() missing 1 required positional argument: 'first_name'
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