[VIDEO PLAYBACK]
DAVID MALAN: --the equivalent C version.
So guess what else we can do with Python?
Not only can we re-implement all of weeks one through five's examples from
C in Python, so can we implement the entirety--
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DOUG LLOYD: That was his.
So, much like a number of the staff, I actually had not extensively
programmed in Python myself.
And so I was actually sitting in the audience
when this lecture was being filmed.
I don't remember you doing this at this time in the lecture, though.
DAVID MALAN: Sometimes entire blocks of material slip my mind,
and we realize after shooting a two-hour lecture,
oh shoot, forgot an additional example.
And this one has actually been important, I think,
so this is the example in which we translate problem set five in CS50
from C to Python, the spell checking problem set.
And the whole point, and we've done this for years in PHP as well,
is to demonstrate just how much more quickly
and with how many fewer lines of code you
can implement the exact same functionality
in a higher-level language like PHP or Python
and to show also the price you pay, typically,
in performance because of the overhead of interpreting the source
code in Python.
DOUG LLOYD: Right, because it's not pre-compiled
so you have to deal with that step.
DAVID MALAN: Indeed, now we're not-- yeah, exactly,
not manually compiled as students might have with Clang, for instance,
in the world of C. So, yes, this is a bit of movie magic.
We might have shot this after the lecture wrapped and then went back in,
and our team kindly sliced it in earlier.
And no one would know this--
DOUG LLOYD: --but for the fact that this is CS50 explained,
and we have a chance to talk about it.
DAVID MALAN: Thanks for explaining that.