1. Python 2
Variables, Assignment and
Types

2. Personality Tester
yournumber = input("Please enter a number between 1 and 99: ")
print "You entered " , yournumber
print "Performing personality analysis on your number choice …"
if yournumber < 49:
print "You are truly inadequate"
else:
print "You have delusions of grandeur"
print "That's all folks"

3. Values
• A basic thing – a letter or a number
• Values have TYPES
• Integers 1, 29485
• Strings “Hello world”
• Float – floating point 3.14159

4. Variables
• A variable has a value
mynumber

5. Variable names
• Can’t begin with a number
• Can’t contain spaces or other funnies
• Can’t be a keyword
– Type help() and press return
– Then type keywords in the box.

6. Assignment
Putting a Value ‘into’ a Variable
• myVariable = 23
• myLongVariable = “Hello how’s it going”
Sometimes written with an arrow
• myVariable 23
Assignment is really a sort of COPY
Why?

7. Assignment quiz
• What’s the value of myVariable
myVariable = 22
mySecondVariable = 13
myVariable = mySecondVariable
myVariable = str(myVariable)

8. Statements
• A statement is a piece of code that
Python can execute.
• Lots of statements make a script
• Scripts are the same as programs

9. Operators
• Operators ‘do things’ to operands
• The simplest operators are the math
+ addition 5+2
- subtraction 5-2
* multiplication 5*2
/ division 5/2
** exponentiation 5**2
% modulo 5%2
Now we can do the first part of the Python Challenge!

10. A useful program
• Write a Fahrenheit to Celsius converter
• The formula for the conversion is: F = 1.8 * C + 32
• To make this program work you will need to do the
following:
Get the user input using input(“your prompt here”)
Assign the result to a variable.
• That will give you a number, but it will be in a string type.
You’ll need to convert it to an integer type using
int(variablename).
• Now you have an integer, multiply it by 1.8 and add 32
• Print the result – your answer, to the screen with
print variablename

11. Challenge
• Write a script/program that allows you to
input two numbers and calculates their:
– Product
– Sum
– Difference
– Quotient (one number divided by the other
without any remainder)
– Remainder (remainder when one is divided by
the other)
– Exponent (one number to the power of the other)

12. Challenge 2
• Create an object
• Find its type
– Print (type(myobject))
• Find its id
– Print (id(myobject))
• What is that?