Python Jumpstart by Building 10 Apps Transcripts
Chapter: App 10: Movie Search App
Lecture: Exploring the search API: The Pythonic Version
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Now, I told you there is two things that we can improve here
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and let's comment this out, let's first work on this part here,
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and in order to understand what is going on,
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with what I am about to write,
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there is a new concept which we have not talked about yet,
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involving keyword arguments that's the orange or reddish values here,
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where you name the parameters, they are not positional, they are named,
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and dictionaries.
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And, if I wrote a function that took keyword arguments,
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I might have one positional parameter 1 and then I can say
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there is a kwargs now this is just a name for a parameter, it doesn't mean anything,
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kind of like self is the convention but not required for classes
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and I can tell Python **kwargs and that means this is going to be
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sort of extensible set of parameters that can be passed
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and is actually going to come in such that this is a dictionary.
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With that in mind, what you can do is
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you can kind of do the reverse with dictionaries,
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so this takes a bunch of arguments that are written like this,
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and turns it into a dictionary,
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but if I have a dictionary I can turn this into a bunch of assignments like this
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during a method call, so I can come over here and say
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I have this dictionary it's called result
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and I would like to say title=results of title, poster=results of poster, and so on,
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I can just say **result, that's it.
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Now if I run it should operate exactly the same boom,
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it does, you can see title set, poster set and everything isn't that cool?
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That's improvement one.
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Let's keep going Improvement two is
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we saw with list comprehensions and generator expressions
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that we don't really need to make a list and append to it
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if all we want to do is build up this list,
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so we can come over here and say you know what,
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movies are actually going to be... some kind of movie results object
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that is generated from let's call this, something simple like m for m in results:.
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So we are going to basically loop over the results, get the dictionary m,
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we are going to unpack it, into this movie results named tuple
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and for each one of these we are going to build a list that has these items in here.
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So again, this should operate exactly the same.
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There you go, I can show you he whole thing, if I can type,
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so you can see we have a list of movie results,
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and just compare line 36 to 39 which if I really wanted to go crazy on you
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I could write like this but I am not going to, right,
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this would be valid Python if I wanted it to be,
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but I much prefer to read in this style, compare that, those 3 lines, to this.
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When you hear people talk about Pythonic code,
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that means it's conforming to the sort of best and proper idioms
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that are part of the Python language. You see code written like this,
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you are like oh these people are taking some other language idioms
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like maybe C or Javascript or something like that
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and just converting it over just such that it will run in Python
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but not like deeply embracing the language,
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down here, this is an example of something you might call Pythonic, I mean,
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look how much more amazingly readable and awesome this is,
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it's easy to maintain, now granted you've got to know Python a little better
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to understand what's going on, but once you do, oh how sweat.
