Python is the language I know the most, and strangely I still don't know why I'm typing "self" and not "this" like in Java or PHP.
I know that Python is older than Java, but I can't figure out where does this come from. Especially since you can use any name instead of "self": the program will work fine.
So where does this convention come from?
Smalltalk-80, released by Xerox in 1980, used self. Objective-C (early 1980s) layers Smalltalk features over C, so it uses self too. Modula-3 (1988), Python (late 1980s), and Ruby (mid 1990s) also follow this tradition.
C++, also dating from the early 1980s, chose this instead of self. Since Java was designed to be familiar to C/C++ developers, it uses this too.
Smalltalk uses the metaphor of objects sending messages to each other, so "self" just indicates that the object is sending a message to itself.
Check the history of Python for user defined classes:
Instead, one simply defines a function whose first argument corresponds to the instance, which by convention is named "self." For example:
def spam(self,y):
print self.x, y
This approach resembles something I had seen in Modula-3, which had already provided me with the syntax for import and exception handling.
It's a choice as good as any other. You might ask why C++, Java, and C# chose "this" just as easily.
The primary inspiration was Modula-3, which Guido was introduced to at DEC:
the Modula-3 final report was being written there at about the same time. What I learned there showed up in Python's exception handling, modules, and the fact that methods explicitly contain “self” in their parameter list.
I think that since it's explicitly declared it makes more sense seeing an actual argument called "self" rather than "this". From the grammatical point of view at least, "self" is not as context dependent as "this".
I don't know if I made myself clear enough, but anyway this is just a subjective appreciation.