Which part of the loop is it going through in this class frame?
On Wed, 07 Mar 2018 16:57:51 -0500, C W wrote:
> I am new to OOP. I'm a bit confused about the following code.
> class Clock(object):
> def __init__(self, time):
> self.time = time
Here you set the instance attribute "self.time".
> def print_time(self):
> time = '6:30'
Here you set the local variable "time", which is completely unrelated to
the attribute "self.time".
If you are used to languages where "foo" inside a method is a short-cut
for "self.foo" or "this.foo", Python does not do that. Local variables
and instance attributes are distinct concepts, and Python keeps them
> How does line-by-line execution run inside a frame?
There isn't actually line-by-line execution as such, although it can be
very similar. Before the interpreter runs Python code, it compiles it to
byte-code, and then runs the byte-code. A single line of source code
could result in any number of lines of byte code, from zero to an
> How does __init__
> work? I understand you must have __init__.
You understand wrongly then :-)
It is normal and common to have an __init__ method, but it is not
compulsory. If your class doesn't need one, you don't need to write it.
The __init__ method is the initialiser. Think of it as very similar to
the constructor in some other languages, and for now the differences
aren't important. The usual purpose of the __init__ method is to
initialise the instance and set any attributes needed.
> Is it run before print_time(),
The __init__ method is called once, when the instance is first created.
So the short answer is, yes, it will run before print_time(). But only
> if so, why don't I just set self.time = '6:30' instead of
> self.time = time?
Because then every instance will be set to 6:30, instead of letting you
set each instance to a different time.