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Like in the previous lecture, I showed you how to automatically execute a script when the writing is

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pallett up.

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And we did it by adding some code inside the to a program.

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Of course, if you don't want that to actually happen and you want any code to be executed when there

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is power up, then make sure that there's no executable code in this file.

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Or you can just delete this file and recreate it later when you need it.

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So I'm going to put this away from now.

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And in this lecture, which is the last one for this section, I want to show you a few techniques useful

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when you do debugging and troubleshooting of your macro Python script.

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So I've got the Blink script here, and the first thing that I've done in order to help me with troubleshooting

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is to use print statements.

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If you come from the Adreno world, then you are familiar with how we use print statements there to

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try and figure out what is happening during the runtime, during the time that our script or our sketch

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is being executed on.

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And that is a similar principle here.

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Again, I'm using print statements to print out in this case what is happening with this particular

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object, and I'm printing out its value.

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So when I run the current script, you can see that here it is on then I get no one for value when it's

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all gets zero and so on.

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So this is telling me that the ality object is behaving as I expect it to behave.

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So control it is stupid and clear.

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So another thing that you can do is to read the comprehensive usually error messages that come from

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Python when there is a problem.

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So the Python interpreter, it's actually pretty good at providing information about what has gone wrong

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with the execution of a script.

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First of all, look at a couple of examples.

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Let's say that we are trying to access Tapio that doesn't exist.

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So it's just an honest mistake here.

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It's sent that script to the two and you see a pretty clear error line for.

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We tried to do something with an invalid pin.

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So this is easy to solve, right?

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You've got to for have a look at the pin parameter and fingers.

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You know, which pins are valid for the especially to have you have a pin map nearby, then you know

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that there is no two hundred eleven pin and that he probably meant 21, which is where my ID is connected

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to something with things like other parameters.

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In this case the pin parameter.

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Let's say we only have pin in and pin out as constants for the type of pin object that we are trying

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to create.

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If you had a typo here, again, that would generate a fairly accurate error message saying that again

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in line for you, trying to create an object of a type that doesn't exist.

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Him, that doesn't exist, so you can go ahead and fix that is similarly.

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Any type typically will generate a message that is accurate or you can see in this case, it says line

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13, which is not very accurate.

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Obviously at the end of the script, it's pointing the error at the end of the script, but the name

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error is more appropriate here.

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It gives you more clues to figure out what the problem may be.

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So initially, we will look at line 13.

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You won't find anything strange there.

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You look at the rest of the error message and it will guide you to where the problem is.

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So you may need to carefully assess the entire error message in to trace back until you can figure out

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where the problem is.

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So for things like typos typically have very good accuracy in the error messages to come back from the

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interpreter.

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I'm going to give you one more example.

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Let's say that we have a typo in one of the methods.

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So let's say that we try to insert a parameter in line 13.

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Let's see what comes back then.

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He did execute the program to line 11 and then it very accurately said that there is a problem here.

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The function takes one positional argument, but to given actually this this function does not require

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any commands.

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But in a later lecture, I'm going to explain why you're getting another one here instead of zero.

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But the fact is that the problem here has to do with the number of arguments that we have provided.

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This function does not take any arguments and I have given one.

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And therefore I'm getting into a message.

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It can look at the documentation here as well if.

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You're having trouble figuring out what the appropriate syntax is.

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So in this case, we would go to ESP three to.

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We would go to Pince and Jebril because we have imported the module from machine, and this will tell

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you how to use these particular functions here, you can drill down to the documentation itself and

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get more information about all this, including, let's say, the type of constants that are available

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for the mode.

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So I said earlier this only in Allapattah actually opened drain and out and out of introducers quite

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a few there.

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And having a look at the methods, you'll see that the value can be.

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One or zero, if not providing a parameter, if it's empty.

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And also here is on and off on the paramedics who set into one of facilities zero.

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Again, no parameters.

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So sometimes you may need to refer to the limitation to figure out what is going on.

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All right.

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So I'm going to leave it at that over the next few sections and dozens of lectures will be bumping into

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problems with my scripts.

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And in many cases, I'll be showing you live how I've gone about solving those issues.

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But for now, just keep in mind that it's a good idea to keep print statements, especially if you are

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developing a new script so that you get real time information about what is happening inside the program

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as it's executing and become familiar over time with reading those traceback error messages from the

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Python interpreter.

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And I guarantee that every single time to be able to fix the.