Python Memory Management and Tips Transcripts
Chapter: Allocating memory in Python
Lecture: Big objects may actually be many small ones
0:02 As you saw, in just the last video, Python has this Small Object allocator. Well, if small objects are treated differently than other objects,
0:13 you want to know what objects are small and more of them are small than you would think, because most big objects are actually just lots of small ones.
0:23 So let's take a look at one example. There's many we could talk about. So here we've got data,
0:27 a list that contains 50 integers, 1 to 50, and in a lot of languages, the way this would work is you would have just one giant block of memory that
0:37 would be, say, 8 times 50 long for each 8 byte number that's gonna go in there 4 times that right 200 bytes if they're regular integers and so on.
0:47 And it's just one big thing. But that's not how it works in Python. When you put stuff together like this, you're gonna end up with the list that has,
0:56 you know, a bunch of pointers as many pointers as there are in the actual list. Plus probably a few extra for that buffering
1:04 so you don't reallocate like I talked about, but what you're actually gonna do is have a bunch of little objects that are being
1:10 pointed to by the parts of the list. And if you have a class, you're gonna have fields in the class.
1:15 The things that are in there are like strings and numbers and maybe other lists those are not part of that object in terms of how big it is,
1:23 those are outside of there, pointed to by, pointed to by the variables within that data structure.
1:30 So these objects that feel like they're big, often they're many small ones,
1:35 and if that's the case, all of these little things get stuck into the algorithm applied to the Small Object Allocator,
1:42 not a big object. Even though taken as a whole, they might use tons of memory.
1:46 Most of the parts will probably still be effectively as far as Pythons concerned small objects.