#100DaysOfCode in Python Transcripts
Chapter: Days 79-81: Basic Database Access with SQLite3
Lecture: Demo: Script to populate the address book
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So what just saw in the last video,
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inserting data line by line,
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on this Python shell, within this Python shell,
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is actually quite tedious, right?
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Imagine trying to enter lots and lots of data.
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Well, you're not going to do it that way.
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That was just for demonstrations.
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So, what I've done is I have actually written a simple
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populate_db.py Python file,
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which again is in the materials for this course,
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and what it does it actually prompts you to enter the data
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as it is required,
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and you can run it as many times as you want.
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It actually keeps looping through until you quit out of it.
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So, let's take a look at that file here.
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Now, let's create it.
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You're again going to use some magic here.
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You can just copy the file from the actual repo, otherwise,
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just feel free to pause and tuck this in if you're crazy.
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Uh, alright.
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Let's create the file here.
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Let's save the file as
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pop, woops, populate_db.py
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Alright, here comes the magic.
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Alright, let's take a look at that.
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Now, this is nowhere near as complex as
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the generator one we did before.
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So, first things first,
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as soon as you click on this or run this script,
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it's going to run the enter_details function, okay,
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and the inter details function simply starts a while loop
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and while true, which is always true, right?
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Running the script is true.
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So while true, it creates an info list,
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an empty one, right?
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We need to set this here because we are going to add to it,
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in a second.
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Now, it actually runs three inputs and this is where it
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prompts you to enter the data that you want in the database.
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So, name=, or name is input,
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enter a name.
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So, when you enter a name,
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this prompt is assigned to the name variable.
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Same with address, same with phone number.
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Nice and simple.
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Now, for I, we are going to run a for loop for I,
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in name, address, number.
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That's the three variables.
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So, it's going to iterate over them.
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We want to append I,
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so append the name for I,
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so, for name let's just break it down.
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So, for name in name here,
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we are going to append the data within the name
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to the info list.
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Okay, so by running this for loop is where we are
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populating the info list with these three variables.
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Simple as that.
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Now, you remember this from the generator before?
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We have a with statement, okay,
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so it's opening the connection, right,
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and within this width statement
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it is running connections on cursor,
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and then it's executing this SQL here.
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Now, this is the important part.
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So, we are inserting into our details table
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these three values,
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but we are not actually.
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These are actually wild cards, right,
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so these are substituted just like you would with a stream,
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okay, using in the print statement,
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but with substituting the contents of info.
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So this is very manual.
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Just think of it that way.
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What if info wasn't filled with three name, address, number,
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three list items?
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What if it wasn't?
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Well, this wouldn't work.
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So this was written specifically for our address book table,
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details table,
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because we know it has three columns: one, two, three;
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and we are going from left to right,
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name, address book, phone number.
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So, if again, if this info was any other way,
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this would mess up.
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Likewise, if someone wrote an address into enter name,
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and a name in enter address,
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you're going to end up putting an address into the name column
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and the name into the address column.
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So, just bare in mind those limitations,
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but the reality is inserting the info list populated
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with name, address, and number into your database
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and then it simply prints data inserted to database.
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Then, it asks you if you want to stop.
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So, if you hit q, in any case,
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it's going to break out of the script.
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Otherwise, it's just going to continue on
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and go back to the top and ask you the same three questions.
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So, let's save this file.
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Lets exit out of our shell
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and let's run it Python populate_db.py
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So, enter a name.
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Let's just give us some white space there.
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Now, the name is going to be Bob.
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What's Bob's address?
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Somewhere over the rainbow.
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Isn't that lovely?
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And a phone number.
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Let's go backwards.
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Alright, that's Bob's phone number.
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Data inserted to database.
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Hit q to quit.
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Ooh, there we go.
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We go back to the start.
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So let's enter name, Mike.
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Where does Mike live?
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The US of A.
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And his phone number?
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As per every US phone number I see on TV 555,
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something else, let's go with 3226.
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Data inserted to database.
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Alright.
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We'll hit q to quit and we get out of the script.
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Done.
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Alright, and it's safely closed and everything
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because the SQLite connection was wrapped
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in that with statement.
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Refresh our database table
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and there we have the new data.
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So you can take something like this script,
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put it into some sort of automation,
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and then you'll be able to add people,
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or users, or whatever to your database.
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Imagine this in a Flask script.
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Pretty cool.
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Alright well, enjoy that and.
