Filters

Quick reference

• 00:04 Okay, in this video, I want to talk about filters.
• 00:06 And filters allow us to do things to our variables on our web page.
• 00:10 So if we go back to the Django docs that we've been looking at,
• 00:14 we can scroll down to Filters.
• 00:16 And the format is just use a pipe next to the variable and
• 00:19 then just call whatever filter you want.
• 00:21 So there's a bunch of filters,
• 00:23 we're going to look at some of the more popular ones in just a second.
• 00:26 But for now, let's just use this lower one.
• 00:30 This will change everything in your variable to lowercase.
• 00:34 So let's head back over to our code and look at our views.py file.
• 00:37 We have these two variables, f_name and l_name, John and
• 00:41 Elder, capital E, capital J.
• 00:44 And we're passing them each into our page through the context dictionary,
• 00:48 where we can reference them as first_name and last_name.
• 00:51 So if we come over to our about page, we have this first_name,
• 00:54 last_name variable listed here.
• 00:56 Well, let's say we we didn't want it to be capital E and elder.
• 01:00 We could go pipe and then lower, right?
• 01:04 So let's go ahead and save this and head back over to our page, and click Reload.
• 01:10 And we're going to look right here where it says John Elder.
• 01:13 Boom, now it says lowercase elder, that's very, very cool.
• 01:16 So, Python is an object oriented language.
• 01:19 And usually with object oriented things, we can do objecty things, too,
• 01:24 for instance variables by slapping a period at the end of it and
• 01:28 then doing the object oriented thing.
• 01:30 So a lot of times you would take your variable and go variable.lower, and
• 01:35 that does the same thing.
• 01:37 Well, this sort of allows us to do kind of the same thing,
• 01:40 only through the Django template language on our actual webpage.
• 01:44 So very, very cool.
• 01:45 So head back over to the Django documention and
• 01:48 look through the filters list.
• 01:50 And if we scroll down here, you can see a couple of things that are interesting.
• 01:54 You can build your own custom filters, right?
• 01:57 We're not going to talk about that in this course, but
• 01:59 if you're interested in that check out this link right here.
• 02:02 A lot of this is more advanced, but you could build your own filters, or
• 02:05 you can look at this built-in filter reference.
• 02:07 So, I'm going to open this.
• 02:09 And this just is a big list of some of the more popular ones.
• 02:14 Capitalize first for instance, let's take a look at that one.
• 02:17 So let's head back over to our document or to our code.
• 02:21 And I'm going to change this to lowercase elder, right?
• 02:25 So save this, now let's say we wanted to programmatically change this to
• 02:30 capitalize the first letter.
• 02:32 We would just type in capfirst, save this, come back to our page and hit Reload.
• 02:38 And boom, now it's capital E and elder.
• 02:40 So you can go through here and you can see there's a whole long list of these things.
• 02:45 We're not going to go through all of them in this video.
• 02:47 I'll pull out a couple more that we can look at.
• 02:49 They're kind of fun.
• 02:50 For instance, let's look at upper.
• 02:52 Roll back our code, instead of capfirst, let's go upper, save this.
• 02:57 And back to our page and hit Reload, and
• 03:00 then you can see every single letter is uppercase.
• 03:03 That's kind of cool.
• 03:05 We can cut out different letters or things.
• 03:09 So let's say we want to get rid of this d in elder.
• 03:12 We can use the cut filter, which is just cut, and then colon, and
• 03:17 then quotation marks, and then whatever you want to cut out.
• 03:21 So let's say we want to cut out the d in elder.
• 03:24 So if we save this, come back here and hit Reload,
• 03:28 E-L-E-R, and you notice it's lowercase again.
• 03:31 We can string these together.
• 03:34 So let's use the capfirst and we want to cut out the D in Elder.
• 03:40 So we want the capital E to begin with, we want the D to be cut out.
• 03:44 So head back over to our code.
• 03:47 And we just do that by putting another pipe,
• 03:50 and then typing in whatever you want.
• 03:54 So we put capfirst, let's save this, come back here and hit Reload.
• 03:59 Boom, John Eler, the D has been cut and first letter has been capitalized.
• 04:05 We can do a word count.
• 04:07 How many words are in our variable?
• 04:09 Well, we know just looking at it that there's only one word, right?
• 04:13 So let's get rid of all of this, let's go wordcount.
• 04:16 So we save this, come back here and hit Reload, boom, 1.
• 04:20 There's only one word.
• 04:21 We can do length, length is kind of a fun one.
• 04:24 Let's go length, how long, how many characters is our variable?
• 04:30 Back here and hit Reload, boom, 5, why is that?
• 04:33 Because our variable is elder and that has 1, 2, 3, 4, 5 characters.
• 04:40 Very cool and really easy to do.
• 04:41 So if you're interested in these and you want to learn all of them in great detail,
• 04:46 check out this webpage.
• 04:47 It`s just in our Django template page that we've been working on.
• 04:51 Click on Filters, scroll down to the bottom of the Filter section.
• 04:55 And then click this built in filter reference.
• 04:57 And I'll put a link to this in the reference notes to this video.
• 05:00 So that's all for this video.
• 05:01 In the next video, we'll look at tags.

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