compare-method added to Vector class in lib.py

[Andrwaa]

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[tianyizheng02]

Could you move the method higher up in the file, before all the public methods? Having this one dunder method within all the public methods, rather than having it alongside all the other dunder methods, makes it harder to find.

[tianyizheng02]

Suggested change

	def __eq__(self, vector: object) -> bool:
	"""
	performs the comparison between two vectors
	"""
	if not isinstance(vector, Vector):
	return NotImplemented
	def __eq__(self, vector: Vector) -> bool:
	"""
	performs the comparison between two vectors
	"""

I don't think it makes sense to allow comparison with any object, only with other Vectors.

[Andrwaa]

I tried writing Vector insted of object but it gave me an error that saying: Argument 1 of "eq" is incompatible with supertype "object"; supertype defines the argument type as "object" [override]
This violates the Liskov substitution principle

[tianyizheng02]

linear_algebra/src/lib.py:98: note: This violates the Liskov substitution principle
linear_algebra/src/lib.py:98: note: See https://mypy.readthedocs.io/en/stable/common_issues.html#incompatible-overrides
linear_algebra/src/lib.py:98: note: It is recommended for "__eq__" to work with arbitrary objects, for example:
linear_algebra/src/lib.py:98: note:     def __eq__(self, other: object) -> bool:
linear_algebra/src/lib.py:98: note:         if not isinstance(other, Vector):
linear_algebra/src/lib.py:98: note:             return NotImplemented
linear_algebra/src/lib.py:98: note:         return <logic to compare two Vector instances>

Sorry for the inconvenience, I hadn't realized that mypy treated this as an error. Would you mind changing the code back to what you had originally, with the NotImplemented check? (The method's new location is fine.)

[Andrwaa]

ok, i went back to the previous version

[tianyizheng02]

LGTM, thanks for your changes!