Python - Updated

• Computing
• Lower Secondary (Key Stage 3)

Python 

Year 7 - Lesson 1 

KEY OBJECTIVE

To program a computer using the python programming language

PRIMM

We will be using the PRIMM approach when we learn to code

Predict

Run

Investigate

Modify

Make

Task 1 - PREDICT

What do you think this code will do?

What will the code do?

RUN

run the code

INVESTIGATE and MODIFY

Using the code you have try and:

• make it say a different message
• Make the message print 3 times by calling the procedure multiple times

MAKE

Create your own program that will:

• Have a procedure called "computing" that prints the message "I love computing"
• In the main code call that procedure
• Here is a blank coding window

What is Syntax?

• The way we write a line of code is important, as the computer needs to recognise it.

• Think about our 'English'. It is important that we use correct punctuation, such as Commas and Full Stops. If we didn't, it would make our writing difficult to read.

• If we do not use the correct symbols and spellings in our Python coding, then the computer will not be-able to run our programs.

What is debugging?

• Debugging code refers to the process of identifying and fixing errors, bugs, or defects in a computer program that we have created.
  

• An error occurs, when you have done something wrong in your program. You could have spelt something wrong or even missed out a symbol...

Debugging Continued...

Create with code, shows you where your error is. Below is a screenshot that shows this.

Task 2 - Debugging

In this task, you will need to debug the code using the error messages that create with code provide.

Click here

Variables 

• In programming, a variable is like a container that holds a piece of information. This information can be anything, like a number, a word, or even a whole sentence!

• For example, imagine you have a box that can hold a piece of fruit. You can put an apple in the box, and then later on, you can take the apple out and look at it or even swap it for a banana. In programming, a variable is like that box. You can put information into the variable, and then you can use that information later on in your program and change it as you please.

• To use a variable, you first need to give it a name. This is like labelling the box with the word "fruitbox" so you know what's inside. In programming, you can choose any name you want for your variable, as long as it follows certain rules. For example, the name can't have spaces in it, and it can't start with a number.

Task 3 - Variables - Predict

PREDICT

What do you think the code will do?

RUN

run the code

INVESTIGATE and MODIFY

Using the code try the following:

• make the program call the other two procedures
• Change the name in the printing2 procedure to your name
• (Harder) Add more text after the greeting in printing3 so it will print the following --> "Hello Sally , nice to meet you"

Taking input

We can ask the user for inputs into our programs.

So lets get the computer to do this

PREDICT

What do you think this code will do when run?

RUN

Run the program

INVESTIGATE AND MODIFY

Try and do the following:

• change the procedure name for printmyname() to printname()
• add two more input questions to the askmestuff() procedure about a favourite hobby and place in the world and store them in suitable variables
• add another print statement to the same procedure to print suitable text using the new stored variables.

MAKE

Create your own program that:

• has a procedure that asks 2 questions and stores them as variables
• calls this procedure from the main code
• results in a sentence being printed, using the stored variables
• Here is a blank coding window

Syntax errors?

Let's test some of those error checking skills

On the next drag and drop which bits of code are correct and which would cause an error?

CORRECT

CAUSE AN ERROR

print = ("Hello")

Print("Yes!")

print("this one)

name = imput("what is your name")

name = input("what is your name")

print("this text")

fav colour = "Green"

age = 10

print("Hello", name)

print("Bye",name")

Commenting our code. What is the importance?

• By commenting our code,  it tells you (the programmer) and anyone else who looks at the code what it does.

• By using the '#' symbol, it will not display when your code has been run.

• You have been seeing them since we started but you have to start using them to help you explain what you are doing

What symbol do I use to comment code?

What is the process of checking a program for errors by running it and fixing the issues?

1. Error checking
2. De-bugging
3. Error finding
4. Mistake finding

What type of information can be stored in a variable?

1. Only videos
2. Only sounds
3. Only pictures
4. Numbers, text, and other types of data

Adding conditions

We have been taking inputs, storing variables and outputting results to the screen

Now we need to add some conditions.

PREDICT

What do you think this code would do?

RUN

Run the code

Investigate and Modify

Change the code here to do the following:

• Change the condition to check if the name is equal to "Bob"
• if it is "Bob" then say "Hey there Bob! I know you!"
• else then print out "Have you seen Bob anywhere?"

MAKE

Make a program that

• Has a procedure called checkfood():
• Ask the user to enter their favourite food and store it as a suitable variable
• Check if their favourite food is "pizza" or not
• If it is then print something positive about it
• If it isn't then say something negative about it
• Call the procedure you made in the main code routine
• Here is a blank to code in

If this, if that

• Sometimes we need to check for more than one thing
• And we need to check for certain things in a certain order
• This is where "elif" comes in 
• it stands for ELSE IF
• you only check the elif when the first if has failed
• you can then add as many of these as you like
• and they get checked in order until one if met
• if none are met then the code under the ELSE part will run

PREDICT

RUN

try running the code

Investigate and Modify

With this code try and:

• Edit the names and responses the code is looking for in the various statements
• add an additional elif statement to look for an additional name

MAKE

Make your own version of an if/elif/else statement which:

• Has a procedure defined appropriately
• asks the user to enter a favourite animal
• checks the animal against 4 different animals, each with a specific response if they are selected
• prints that it doesn't like the animal if it is not one of these 4
• calls the written procedure in the main code routine
• You can use this blank

Debugging task

Try and fix these faulty if statements