Matplotlib Tutorial 18 - annotating last price to edge of matplotlib graph example

Key Takeaways

what is going on everybody welcome to part 18 of our matplotlib tutorial series in this part what we're going to talk about is an example of using annotations to plot stock price outside of the graph kind of so when we plot a stock chart a lot of times it's it's hard to see like you can look at price on the left hand side there and you can kind of see what you know the current price is but a lot of times we care very highly about what's like the current last price so like with eBay for example it's like I don't know what I know what the current price is I mean I guess we would go with the close and it's probably here is the close or here is the close but we really don't know and that's anywhere between 61 and 61.5 so a lot of times what people want to do is they want to have an annotation of price over to the right hand side so this would be like an example of a graphing application that's doing that I just typed in like stock prices to Google Images and found this so a lot of graphing applications will do that they'll annotate the price to the right hand side mirror where that last price is and then it moves so it's really easy to find out hey what was the actual last price so a lot of people were asking me about this in my tkinter series and I just never got around to adding it but this is how you do it so we'll close out of this and close out of this and let's go ahead and add that now and so with annotations it's it's really not too much on top of what we've already you won't really won't learn anything new it's just an example of you know putting this to work so first I'm going to get rid of these annotations here so I'm just gonna highlight all of these and alt 3 that comments them out and in fact actually let's do let me just leave a note here annotation example with arrow and then down here this was our font dict example and then finally I don't know hard coded text okay and then I'll go this and now all three this okay so now what we're going to do is we're going to place what we would do like an annotations here so we would say ax 1 dot a note 8 and what we would annotate here is something like we would do the string of close P minus 1 so that's the like what is the text that we want to annotate here well we want to annotate whatever the last price was but that's gonna mean int so we're actually to float spoke we want to convert that to a string so we're doing that first so that's the last price then we have to like what are we annotating basically and so that would be like where is this going to be located so we want to annotate that and the annotate that it's like you know basically pointing to is date minus 1 and then close P minus 1 this one doesn't matter so much but it you know it could it depends on how you want to handle this but in our case it really won't make too much of a difference and then now we're gonna say XY text and before remember we did this as an axis for action well we're not going to do that because we actually we want this to kind of move dynamically with the price so we would say XY text equals date minus 1 so what was the last date and then what we're gonna do is we would add some to it because again this is actually the if you pay attention you can see here this would be your spine and this would be your spine and the annotation of price is usually like off-the-charts so to speak it's it's off of the graph so we want the same thing so we're gonna say the last date that's our x-axis so we're gonna say the last date plus let's do for for now and so that will hopefully move us over quite a bit and then we're you know where is the y that we want this well generally you place that annotation dynamically up or down in accordance to the price so for us we wanted we want it to be exactly where that P is so we're gonna say close P minus one and that really can be it but we can add a little bit more so first let's like bring this up and let's see how that looks non keyword argument what are we doing here XY text so we forgot to put this in parenthesis there let's try it one more time I'm still getting invalid syntax here what have we done so we I guess we just totally forgot yeah the parenthesis there so now we can see that at least we have the price that we're running us we don't really have the space here so we can well fix that because we already have the adjustments there so we have the price there so we can see the last price was sixty point nine nine so okay we'll close this let's go to the bottom here and on right currently it says point nine four we'll change that to point and I know and then what we're gonna do is come back up to our annotation here where are we there we go and now we can kind of customize that so if you if you can see here we've got so we actually real cover something new congratulations for those who didn't leave right away so you've got like this little box here right like we can we can customize to handle for that kind of situation so for example after we give the XY text we can give one more parameter here and we're gonna say B B well B box equals B Box underscore props and then we'll just add those props right up here so now we're gonna say is B Box underscore props equals so these are just the box properties right so props whenever you see that it's like short for properties we like to give nicknames through our things in Python because we're cool and so P box props will be the dict of and then in here we're gonna say box style and you can give a bunch of box styles so for those of you don't know you can always like like I've tried to kind of illustrate before if there's something you're just not you don't know on matplotlib or really any module you go to google and you type it in so for it in in this example if you want to know more about annotating matplotlib what am I more of my options you would type in matplotlib annotate hit enter on Google and you find yourself probably on this page and so this gives us all the kind of examples of annotations that we might might have and then down here these are kind of like the styles that are possible here and then these are kind of like visual examples of what those styles would look like so either round or maybe round 4 or the left arrow would be you know valid choices here so let me move this over again and so we're gonna say box style that's what we were just looking at was box styles we're gonna say box style equals and we'll just do the round let's choose that round option and then you can add padding if you want we're just gonna leave it alone for now and then you've got face color and edge color okay so face color we're gonna say the face color is white and then the edge color will make black which is K so W is short for white K is black because B is blue so anyway and then we can change the line width if we wanted I think we'll leave that for now we'll say line width equals 1 just so you can change it if you want but that's about it so there are a bunch of parameters there for our box here let's run it now and see what we're looking at all right so now you've got kind of like this box here that has our price of course our default load is still kind of man we should kind of give ourselves some more space on the bottom in the left so let's go ahead and change that to for those of you who are following linearly so bottom will give it point two four and left will give point 11 see how we do now beautiful we need a little bit more right though but anyway okay cool so that's looking pretty good so you could also do like that gives us the price but you could also go with like the left arrow for example so instead of round we can do I think it was L arrow L arrow like that find out yeah okay so there's that I'm just not I'm not the biggest fan of that little arrow I kind of like you know the round is probably my favorite but the arrow is a little more explicit and like what it's actually doing so you can feel free to choose whatever you want I'm gonna go with the round though I like that one the best I think or maybe around four whoops not round four round four that one's kind of good too I don't know you can go with whatever you want I think I'm gonna go back to round anyway that's it for this tutorial if you have any questions or comments up to this point feel free to leave them below otherwise as always thanks for watching thanks for all the support on subscriptions until next time