stricttuple
Python tuples with built in rule enforcement.
How to install it?
pip install stricttuple
This library is designed to restrict the inputs of your code by limiting what the variables can become. This way, you'll know the full scope of what your code is capable of messing up.
Example Usage:
In [1]: from stricttuple import stricttuple
In [2]: Point = stricttuple(
...: "Point",
...: x = (
...: lambda x:type(x)==int,
...: lambda x:x<15 and x>=0
...: ),
...: y = (
...: lambda y:type(y)==int,
...: lambda y:y<15 and y>=0
...: )
...: )This creates read only Point objects with two fields (x and y) that can only legally
be generated if the values of x and y are ints and between 0 and 15.
In [3]: Point(x=5, y=6)
Out[3]:
+---+---+
| x | 5 |
| y | 6 |
+---+---+
So, what happens if we assign x to the string "fish"?
In [4]: Point(x='fish', y=6)
---------------------------------------------------------------------------
IllegalStrictTuple Traceback (most recent call last)
<ipython-input-4-040e8d8fa069> in <module>
----> 1 Point(x='fish', y=6)
~/py3/lib/python3.6/site-packages/stricttuple/__init__.py in __call__(self, **kwargs)
243 type(v).__name__,
244 repr(v),
--> 245 getsource(r).strip()
246 ))
247 nt = self.namedtuple(**kwargs)
IllegalStrictTuple:
------------------------------------
instruction:
Point.x = str('fish')
violates the rule:
lambda x:type(x)==int,
------------------------------------
An IllegalStrictTuple exception is raised along with pinpointing what rule the input violated.
This means we can have debuggable data validation beyond just type checking like the following:
In [5]: Point(x=21, y=6)
---------------------------------------------------------------------------
IllegalStrictTuple Traceback (most recent call last)
<ipython-input-5-d943248369f4> in <module>
----> 1 Point(x=21, y=6)
~/py3/lib/python3.6/site-packages/stricttuple/__init__.py in __call__(self, **kwargs)
243 type(v).__name__,
244 repr(v),
--> 245 getsource(r).strip()
246 ))
247 nt = self.namedtuple(**kwargs)
IllegalStrictTuple:
------------------------------------
instruction:
Point.x = int(21)
violates the rule:
lambda x:x<15 and x>=0
------------------------------------
