PROGRAMMINGIn

STARTER

Using the internet…Find …

what does “case sensitive” mean what a programming language

is.. 3 benefits of Python

OBJECTIVES

Learn about python as a programming language

Learn about expressions & variables and their use

Create several successful programs

Open the ICT levels spread sheet and find python tab Read each Yellow box and answer in the white box.

SELF ASSESSMENT

TARGETS. Open the self evaluation workbook and fill in the boxes in

green ellipse (squashed circle)

This workbook will be used throughout the python unit – DO NOT LOSE IT. It will be used at the end by the teacher to assess your ICT Level.

PYTHON

Python is a programming language A set of words and rules for instructing a computer to

perform specific tasks. The term programming language usually refers to

high-level languages, such as BASIC, C, C++, Python etc Each Programming language has a set of keywords and a

special syntax for writing program instructions.

Learning to program is going to be fun – so lets keep it simple.

org 100hmain proc mov ah,9 ; mov dx,offset hello_message int 21h : retn hello_message db 'Hello, world!$'main endpend main

print ("Hello, World!“)

#include <iostream>int main(){ std::cout << "Hello World!" << std::endl; return 0;}

C++

Assembler

python

WHY PYTHON

WHAT IS A PROGRAM

Programming is not telling the computer what you want to do….it is telling it EXACTLY HOW to do it.

A program is a sequence of instructions that specifies how to perform a computation.

The computation might be something mathematical, such as solving a system of equations

It can also be a symbolic computation, such as searching and replacing text in a document or moving a graphic icon (sprite) on a game.

TRADITION It is tradition that the first program everyone

creates is to say Hello world”. From the start menu – all programs / python 3.3 /

idle Open Idle(python GUI) MAKE SURE YOU ARE IN THE PYTHON SHELL

Enter the following and press enter

print (“Hello, World”)

This one

If you see this window on top – look for the python shell window.

EXPRESSIONS

Try typing some of these expression in idle, pressing return after each one

print (2+2+2+2+2)

print (8*6)

print (10-5+6)

print ( 2  +       2)

Remember to press F5 to save the program first

otherwise it won’t run.

• EXPRESSIONS

You have been using expressions

2 values and an operator

Even the 2+2+2+2 follows this rule

Operators, you already know.

Perhaps the multiplication is written differently as a * (on the number pad)

At the moment python is acting like a calculator.

2+2 addition

2-2 subtraction

2*2 multiplication

2/2 division

• SYNTAX

In computer science, the syntax of a programming language is the set of rules that define the combinations of symbols that are considered to be correctly structured programs in that language.

Aka syntax means that special key words and characters combine to result in a program.

• SYNTAX

The syntax of a programming language is the set of rules that control if a program is correct.

You tried print (“Hello, World”) and it worked – a correct program.

Try these

print hello

print (hello)

PRINT(“hello”)

print (a + b)

print (5 + 6 / 7 +)

Syntax is CRITICAL in programming. A computer cannot take an educated guess at your instructions.

Computers just follow exactly what you tell them to do.

VARIABLES

A variable is just a box with a number in it.

When we use variable in our code the computer uses the value in the variable.

To store the value 15 in the variable and display it

spam = 15print (spam)

Try it.

Now try these

spam = spam + 12

print (spam)

spam = spam + spam

print (spam)

spam = spam * spam

print (spam)

VARIABLESThis time we have 2 variables eggs and fizz

You can assign them by

eggs = 15

fizz = 10

What be the output of the following, go on try it.

print( eggs )

print( eggs + fizz )

spam = eggs + fizz

print( spam )

eggs = fizz

print( eggs )

print( EGGS )

1525>>>nothing25>>>nothing10Traceback (most recent call last): File "<pyshell#37>", line 1, in <module> EGGSNameError: name 'EGGS' is not defined

In python eggs is not the same as EGGS.Python is case sensitive which means YOU MUST BE CAREFUL

COMPLETE SELF ASSESSMENT QUIZComplete Self Assessment quiz from lesson 1

CHALLENGE TIME

Create a program to calculate the perimeter and area of:1. A Square2. A Rectangle3. A Triangle4. A Circle

Can you create a program that asks the user to input the length and widthand then the program calculates the perimeter and area for them.

PLENARY

And update your self-evaluation for this lesson.