On 05/23/2013 03:57 PM, Citizen Kant wrote:
It's quite hard to believe that you're not just trolling. Little that
you say below makes any sense with regards to Python.
I guess I'm understanding that, in Python, if something belongs to a type,
must also be a value.
Nothing belongs to a type. Objects created during the running of a
program do have a definite type, and a definite value. Some are
immutable, meaning they cannot change. Others are mutable. Examples are
int and list, respectively.
I guess I'm understanding that the reason why 9 is considered a value, is
since it's a normal form*,* an element of the system that cannot be
rewritten and reduced any further.
9 is a numeric literal in your source code that describes the integer
nine. Since it starts with a digit, and does not have quotes around it,
it will be represented in the virtual machine as an integer object.
I also guess I'm understanding that the same goes somehow for the letter A
for example, since it cannot be rewritten or reduced any further, so it's a
value too.
The letter A in your source code might be almost anything. If it stands
by itself, or is surrounded just by letters and digits, then it's a
name, or identifier, presumably defined in some namespace.
That same A in the source code could be part of a string literal, if
it's between quote marks. The quote marks are not part of the string,
they're merely part of the literal representation. The language parser
has to have some way of deciding whether you meant it as a name, or as a
string. The quotes define that.
type('A')
<type 'str'>
The question is, in order to understand: does this apostrophes thing has a
more profound reason to be attached to the letters or it's just a
conventional way to set a difference between letters and numbers?
Letters and numbers can both be used inside a string literal. What
makes it a string literal is the presence of quote marks.
Do I must
observe this apostrophes thing like the symbol of the type itself inside
which one can put any character, setting it as type str?
No clue what that's supposed to mean.
When the compiler processes your source file, it tokenizes it into some
byte code. When that byte code executes, objects are created,
identifiers are bound and unbound to those objects, expressions are
evaluated, functions are called, and possibly external devices are
spoken to.
A string object has no quote marks around it (unless you go out of your
way to add them to the string explicitly), and an int object has no
definite format that is defined in the language. They both have values,
and sometimes its convenient to describe those values in the terms of
source code. But an int object for example is unlikely to be in base ten.
--
DaveA
_______________________________________________
Tutor maillist - Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor
