Python 3, an illustrated tour Transcripts
Lecture: Long Unification
0:00 In this video we're going to talk about pep 237, came out in Python 3
0:04 and this is the unification of long and integer types.
0:07 From the pep it says there is also the greater desire to hide unnecessary details
0:11 from the Python user when they're irrelevant for most applications.
0:15 It makes sense to extend this convenience to numbers.
0:18 If you're familiar, in Python 2 there was a long integer type
0:22 and a normal integer type.
0:25 And you could tell one from the other
0:27 because when you print it out a long type there was an L after it.
0:30 Now Python supports arbitrary precision in integers
0:32 it's only limited by the amount of memory you have
0:35 so you can make pretty big integers if you want to.
0:38 Here's an example of creating big integers
0:41 and we're calling the sys.getsizeof on our integers
0:44 and just seeing that as we create bigger and bigger integers,
0:48 that the number of bytes required to store those integers gets bigger.
0:52 And so what's happening here is that Python's doing an automatic transition
0:57 from the native integers to these longer integers,
1:01 but it's hiding that from you, you don't notice it.
1:05 Typically we don't even inspect a number of bytes that we're using in Python,
1:08 but this just allows us to see that we can make arbitrary large integers
1:12 and they'll just use more memory, but Python will allow us to do that.
1:17 If you're interested in the details of this
1:19 you can look at the c code on python.org or in the GitHub project
1:22 and that's in the include/longintrepr.h and objects/longobject.c
1:29 the details of how this is handled.
1:32 For most people this isn't a big deal because again in Python,
1:36 we just let Python do what it wants to do.
1:38 and if we have an error we deal with the error,
1:42 but typically, when we're dealing with integers or whatnot there aren't errors
1:44 with this and the float division that we saw prior
1:47 a lot of the inconsistencies or warts in Python are hidden away from end users.