updated docstrings, typehints, gitignore, & readme

.gitignore

@@ -102,3 +102,6 @@ venv.bak/
 
 # mypy
 .mypy_cache/
+
+# vscode
+.vscode/

README.md

@@ -13,7 +13,7 @@
 
 - `sysml/system.py` - module for creating a `Model` object, which serves as a central namespace for model elements (and relationships between elements).
 
-- `sysml/element.py` - module for creating model elements (s.a., `Package`, `Block`, `ConstraintBlock`, `Activity`, `Interaction`, `StateMachine`, `Requirement`). These objects are intended to be subsumed by a `Model` object.
+- `sysml/elements/` - modules for creating model elements, divided into 4 pillars: structure, behavior, requirements, and parametrics. These objects are intended to be subsumed by a `Model` object.
 
 ## Developer Notes
 

sysml/elements/behavior.py

@@ -1,10 +1,6 @@
 """
-The `element.py` module contains all model elements that are valid for use by
-the `model` class
-
----------
-
-Model elements are the building blocks that make up SysML
+Behavior of a system, in collaboration with its actors, can be described
+by use cases, activities, interactions, and/or state machines.
 """
 
 from sysml.elements.base import ModelElement
@@ -17,7 +13,7 @@
 class StateMachine(ModelElement):
     """This class defines a state"""
 
-    def __init__(self):
+    def __init__(self, name: Optional[str] = ""):
         super().__init__(name)
 
     @property
@@ -28,7 +24,7 @@ def name(self):
 class Activity(ModelElement):
     """This class defines a activity"""
 
-    def __init__(self):
+    def __init__(self, name: Optional[str] = ""):
         super().__init__(name)
 
     @property
@@ -41,9 +37,9 @@ class Interaction(ModelElement):
 
     def __init__(
         self,
-        name: Optional[str],
-        lifelines: Optional[List["Block"]],
-        messages: Optional["ModelElement"],
+        name: Optional[str] = "",
+        lifelines: Optional[List["Block"]] = None,
+        messages: Optional["ModelElement"] = None,
     ):
         super().__init__(name)
 

sysml/elements/parametrics.py

@@ -38,9 +38,7 @@ class ValueType(ModelElement):
     <ValueType(39.138799173399406, 'light_year')>
     """
 
-    def __init__(self, units: Optional["ModelElement"]):
-        # TODO: Needs to be redesigned to inherit methods of a UnitRegistry
-        # object while also inheriting from ModelElement
+    def __init__(self, units: Optional[str] = ""):
 
         super().__init__(self.name)
 
@@ -52,5 +50,5 @@ def name(self):
 class ConstraintBlock(ModelElement):
     """This class defines a constraint"""
 
-    def __init__(self, name: str = ""):
+    def __init__(self, name: Optional[str] = ""):
         super().__init__(name)

sysml/elements/requirements.py

@@ -1,10 +1,6 @@
 """
-The `element.py` module contains all model elements that are valid for use by
-the `model` class
-
----------
-
-Model elements are the building blocks that make up SysML
+Requirements display text-based requirements (and the requirements
+specifications that contain them)
 """
 
 from sysml.elements.base import ModelElement
@@ -14,7 +10,9 @@
 class Requirement(ModelElement):
     """This class defines a requirement"""
 
-    def __init__(self, name="", txt="", id=""):
+    def __init__(
+        self, name: Optional[str] = "", txt: Optional[str] = "", id: Optional[str] = ""
+    ):
         super().__init__(name)
 
         if type(txt) is str:

sysml/elements/structure.py

@@ -1,15 +1,11 @@
 """
-The `element.py` module contains all model elements that are valid for use by
-the `model` class
-
----------
-
-Model elements are the building blocks that make up SysML
+Structural elements are commonly used to describe system hierarchies,
+classifications, internal composition, or interfaces.
 """
 
 from sysml.elements.base import *
-from sysml.elements.parametrics import *
 from sysml.elements.requirements import *
+from sysml.elements.parametrics import *
 from collections import OrderedDict as _OrderedDict
 from typing import Dict, List, Optional, Union