I have a class with string data, and I'm supposed to calculate hash of the whole object using hashlib.sha256() .
I was not directly able to get hash with
block c for example
Hash = hashlib.sha256(c.encode()).digest()
I want to calculate hash of the whole object,I was suggested to have a function in the class such that it returns hash of data inside it . Is it same as has of whole block ? What is better implementation?
You need to implement the magic method __hash__ for your class. You may then use an instance of your class, for example, as a key of a dictionary. Also, if you just need to get a hash, you can simply use the built-in function hash():
c = MyClass()
c_hash = hash(c)
The current answer let's it appear as if there was a need to define __hash__. As a partly answer, I hence clarify that this is logically false.
One should be able to implement sha256 or the python interpreter such that of a given class object the full hash is taken.
Reason: With pickle dumps it is possible to save an object uniquely to file. The data footprint of that file is digestable; thus it is a mere insufficiency of the language and should be fixable through some boilerplate code.
