Python Jumpstart by Building 10 Apps Transcripts
Chapter: App 5: Real-time weather client
Lecture: Building the beginnings of the weather app
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Before we talk about pip and packages
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and the Python package index and all of those things
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let's just sketch out our app as far as we can take it
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and then we'll bring in the packages.
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So we are going to get started as always by writing a program.py file
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and let's also start this time by defining a main method
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that's going to be sort of the top level method to be called here
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remember, this is not a Python convention, this is just Michael convention,
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so we are going to have to do things like
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I'll just sketch out in comments like print the header
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and then the next thing we have to do maybe is get HTML from web
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so I want to download the HTML,
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then we are going to have to parse, the HTML,
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we have to display the forecast.
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And at some point I suppose we are also going to need
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to actually get the locations, we'll say get zip code from user.
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Ok, so these are the kind of the steps
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and you can see there is little warning
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that's because there is actually nothing happening in this method
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let's just do a print hello from main really quick
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now recall, if I run this there is no run configuration
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so I'll make one by right clicking and say run program- nothing happens,
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our little print statement doesn't show up
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and that's because we have to call main()
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and we saw that this really is not the right way to do it
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if somebody wants to reuse this module, this script,
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if they import it this is always going to run our app,
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so we saw that there was that convention we say, if__name__='__main__'
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then we would run our main() method,
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this is so common, that PyCharm has what is called live templates.
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So I can come over here and you can see that there is main(),
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this is the method I wrote
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but then there is this main which has actually got some code here
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and if I just hit tab it actually auto expands out of here.
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So this is one of the live templates,
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I'll pull those up really quick,
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you can see there is actually a ton of live templates here,
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that you can use, here is the one that we are running
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but for all sorts of various not as Python
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but SQL and Django and so on,
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so let's go ahead and use our main() bit here,
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and in that case we are going to call main().
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So now our job... let's verify runs, still is,
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now our job is to actually start writing these methods and drop this bit.
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So we are going to print the header so we'll just say
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call a method print_the_header(), or print header however you want to call it,
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and let's put this down below, like so
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and remember, all of our headers looked something like this,
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and here it says weather app centered, usually, and the final new line.
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So perfect, that is solved.
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The next thing we want to do is get the zip code from the user,
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so we can say zip, it's not exactly what we want to say
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but let me just start this way for a moment,
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input will say what zip code do you want the weather for,
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and let's give him a little hint, and say like 97201 as an example.
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Now, notice there is a small warning here,
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we have a little problem with zip,
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there is actually two warnings, one is that we are not using it,
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but the more important warning,
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the not using the part is going to go away,
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is that this shadows the built in name called zip,
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zip is a built in function that does kind of map produce like stuff,
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and this is overwriting, basically hiding the zip function for the rest of this method
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so let's change this, I just want you to be aware
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that those types of things can happen,
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so let's change this to code now there is still a warning
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but it's just that we haven't used it yet, so that's not a big deal.
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The last part is to get the HTML from the web
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and we need to go talk about
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where on the web we are going to get this
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but let's just do a print out of the code really quick
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just to make sure everything is hanging together.
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So what is your zip code, it's 01010 five digits perfect,
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everything is working fine, except for we now need to go get some HTML off the web.
