Proposal for adding symbols within Python

[Rocco Moretti]

Björn Lindström wrote:
> Steven D'Aprano <steve at REMOVETHIScyber.com.au> writes:
> 
> 
>>Why does the byte string "\x6f\x70\x65\x6e\x65\x64" have intrinsic
>>meaning when the int 0 doesn't? It certainly doesn't mean anything to
>>non-English speakers.
>>
>>If all you want is human readable byte strings, then just use them:
>>
>>class MyFile:
>>    def open(self):
>>        self.state = "opened"
>>    def close(self):
>>        self.state = "closed"
> 
> 
> So, I guess no one read my explanation of why this an issue about more
> than implementing enums (which is fairly trivial, as we have seen).

I did, but I still don't see why it is an argument against using 
strings. The point you may not appreciate is that (C)Python already uses 
strings to represent names, as an important part of its introspective 
abilities.

##########################################
 >>> import dis
 >>> def f():
	module.klass.method()

	
 >>> dis.dis(f)
   2           0 LOAD_GLOBAL              0 (module)
               3 LOAD_ATTR                1 (klass)
               6 LOAD_ATTR                2 (method)
               9 CALL_FUNCTION            0
              12 POP_TOP
              13 LOAD_CONST               0 (None)
              16 RETURN_VALUE
 >>> f.func_code.co_names
('module', 'klass', 'method')
 >>> type(f.func_code.co_names[1]) is type('a')
True
##############################################

I'll let you dig through the interpreter source to convince yourself 
that, indeed, the names module, klass, and method are stored internally 
as true python strings. The same holds for other namespaces - the names 
are stored as real python strings, in a real python dictionary.

############################################
 >>> class c:
	def foo(self):
		pass
	def bar(self):
		pass
	def baz(self):
		pass

	
 >>> type(c.__dict__) is type({})
True
 >>> c.__dict__.keys()
['baz', '__module__', 'foo', 'bar', '__doc__']
 >>> type(c.__dict__.keys()[0]) is type('a')
True
##############################################

P.S. This may change for other implementations of Python, but the fact 
remains - there is less difference between names and strings than you 
may first think.