Transcript GCSE Computing

Lesson 6
Python 3.3
Objectives.
In this lesson students will learn how to
output data to the screen and request
input from the user.
Students will also learn how to use
variables to store data for use in their
programs.
Python 3.3
We will be using Python 3.3 to learn the basic of programming and
then have look at other languages if there is time.
We will be using the IDLE Interface
Python 3.3
Programming involves using a set of instructions, data and
keywords to tell the computer what to do.
Your first program type and then press enter
>>> print(“Hello World”)
Python 3.3
Which one of these is correct?
>>> print"Hello World“
>>> print("Hello World");
>>> Print("Hello World")
>>> print("Hel World")
>>> prin(Hello World)
Where do you look for errors?
1) Syntax Errors
2) Logical errors
Python 3.3
Task
Using a script – create a program that produces
three lines of text.
Python 3.3
Special characters in text
\n
Creates a line in a string of
text
\t
Creates a tab style indent in a
string of text
\\
Allows a backslash to appear
in a string of text
\”
Allows a speech mark to be
used in a string of text
Python 3.3
Variables
Variables are containers that can hold data.
In most languages variables are declared to be a certain data type
first such as
Strings, Integers, Dates, Real, Characters etc..
In python variables are declared when they have their first value
assigned to them
Python 3.3
Variables
Try the following program
print("Hello this is a variable program")
name = ""
name = input("Enter in your name please: ")
print("Hello ", name)
Python 3.3
Variables
You can use variables to do calculations
Try this program
print("Hello this is a variable program")
num1 = 0
num2 = 0
sum = 0
num1 = int(input("Enter in number 1 please: "))
num2 = int(input("Enter in number 2 please: "))
sum = num1 + num2
print("The total is ",sum)
Python 3.3
Tasks
Watch the three python videos under lesson 01 and then answer
the questions on the worksheet.
Python 3.3
String Functions.
Len(variable) = returns length
Variable.upper() – returns uppercase of string
Variable.lower() – returns lowercase of string.
Variable.capitalise() – Makes the first letter of the string
capital.
Variable.replace(“old word”,”new word”) – Replaces a word
in a string with the new word.
Python 3.3
String Functions.
astring = "Hello World"
print(astring[:2])
print(astring[6:])
print(astring[:5])
Output –
He
World
Hello
Can you workout what the code is doing from the output?