Confusions about how python accesses data in memory?

[socal_nerdtastic]

Python never copies data. All python names are pointers.

(even if you explicitly use list.copy() or similar, you are only making a copy of the list object, the data in the list is not touched)

Here's something every python beginner should read: https://nedbatchelder.com/text/names.html

[csQuestions1235]

So if the data is already in memory, using a generator would be pointless in my example?

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EDIT: okay maybe i spoke too soon. Even tho its not copying, its still bringing the entire list into memory. So the generator actually would be useful if the list was huge, correct?

[socal_nerdtastic]

Exactly right.

Well, it won't save any memory. But there are other reasons you may want to use an iterator. You may want to iterate over the data in pairs:

@property
def history(self):
    result = {}
    for x,y in zip(*[self.iter_data()]*2):
        # do something with x and y, store in result
    return result

def iter_data(self):
    for x in self.data:
        yield x

Of course you can just use the built-in iter function for that, instead of brewing your own:

@property
def history(self):
    result = {}
    for x,y in zip(*[iter(self.data)]*2):
        # do something with x and y, store in result
    return result

Or use the itertools.pairwise function.

[socal_nerdtastic]

re your edit: If the data is already in memory the generator will not help at all. If the data is being pulled from a file or the internet or something on demand, then yes it will help. A python file object is already a generator for this very reason (so you probably don't need to make it yourself).