1. What are variables? Using input()
Computer Programming
BSc in Digital Media, PSUIC
Aj. Andrew Davison, CoE, PSU Hat Yai Campus
2. Variables
What are variables?
Using input()

2. 1. What is a Variable?
A variable is a "named tag" for data used in your programs
"Aj. Andrew"
tag
data
Python treats the tag name
teacher as being a different
name than Teacher
"Teacher" is a string, not the
tag name Teacher

3. Variables Using Number Data

4. Why are they called "Variables"?
a variable can change
(the tag is given new data 5 9
first

5. Many Tags for One Piece of Data
Teacher
"Aj. Andrew"
GreatTeacher

6. Moving a Tag to New Data changing one variable (tag)
does not affect the other
variable
Great
Teacher
"Einstein
"Aj. Andrew"
Teacher

7. Numbers and Strings + means different things for numbers and strings
strings can use "…" or '…'

8. The New Me
the "new" score is the "old" score + 2

9. 2. Have a Program get Input from the User
Write the program "SayHello.py" in
any text ediror (e.g. Notepad, Notepad++)

10. Load the Program into IDLE

11. Run the program in IDLE

12. the program user types this name
the program uses input() to assign the
user's data to yourName, and then prints it

13. Run the Program Many Times
the user types in a different name each time

14. Run the Program in the Command Window
Find the program and then
run it twice.

15. input() reads in a string
The data for variable x is the string "1234"
This data is NOT the number 1234
use int() to change the data from a
string to a number

16. Getting a number as input
The data for variable x is an integer
The data for variable x is a float
(a decimal)
If Python wants an integer input, it
will be upset if the user enters a float

17. 3. Farenheit to Celsius Converter
tempConverter.py
means no newline
str() changes a number to
a string
comments to help a reader

18. Execution
the user typed this

19. Errors in a Program

20. Where's "line 10"?
string() should be str()