1. Computer Programming Fundamentals
Recap session

2. Agenda Variables Lists ‘if-elif-else’ Loops Modules and functions
‘while’ loop
‘for’ loop
Modules and functions
Putting it all together

3. Variables Chunks of the computer’s memory Each has a name
Starting with alphabetic character
Then can be alphabetic or numeric character
Cannot use keywords
Each has a type
int: integer
bool: Boolean value
str: string

4. Lists Lists are an extremely versatile Python data type
They are used frequently so it is important to get to know how to use them
The elements of a list can be anything:
myList = ["Abc", 1, 3.8, True]
A list can even have no items:
emptyList = []

5. Lists The elements of a list may be modified: Some other operations:
myList = ["Abc", 1, 3.8, True]
myList[0] = "ABCD"
Some other operations:
myList.append("DEF")
myList.extend(["GHI",99])
myList.clear()
myList.pop(i)
del myList[i]

6. ‘if-elif-else’ Use to pick different execution paths if score < 10:
print("Pathetic")
elif score < 20:
print("My gran could do better")
elif score < 50:
print("OK")
else:
print("Legendary!!!")

7. The ‘while’ loop We can make the computer repeat statements
One way to do this is to use a ‘while’ loop
For example
The body of the loop is executed while the condition x > 0 is true
a = 1
x = 10
while x > 0 :
a = a*x
x = x - 1

8. The ‘for’ loop
Another kind of loop is a ‘for’ loop which iterates over the elements of a list
We can use the ‘range’ built-in function to make a ‘for’ loop iterate over integers:
for x in range(4):
print(x)
This will print the numbers 0,1,2,3
L = ["Abc", 1, 3.8, True, "XYZ", 21]
for e in L:
print(e)

9. Functions Functions are a way of packaging useful chunks of code
We give the code a name so it can be re-used
We can tailor how the function behaves by the use of arguments
The function may or may not return a value

10. Modules
Modules are a convenient way to package groups of related functions
Defining a module is very easy
Create a new file – ‘shapes.py’ for instance
Add function definitions to the file
Example – ‘shapes.py’
# Utility functions for dealing with shapes
def circleArea(radius=1):
...
def rectangleInfo(width,height):

11. Putting it all together
Generating lottery numbers
Generate random numbers in a range
Need 6 different numbers 11

12. Exercises An exercise in using random numbers
Write a program to generate lottery numbers