Variables - Containers for Data (continued)
Python ·Purpose of Variables
As reminder: You can think of variables as a label. They are always on the left side of the equal sign (=). Take a look at the code below:
basic.show_string(“Who is she?”)
basic.show_string(“Supercalifragilisticexpialidocious”)
basic.show_string(“What’s her name?”)
basic.show_string(“Supercalifragilisticexpialidocious”)
basic.show_string(“Say that again?”)
basic.show_string(“Supercalifragilisticexpialidocious”)
Having to type out “Supercalifragilisticexpialidocious” every single time you want to use it would be annoying, wouldn’t it? Instead, we can assign the string “Supercalifragilisticexpialidocious” to a variable called name and use that instead. Then it would look something like this:
name = “Supercalifragilisticexpialidocious”
basic.show_string(“Who is she?”)
basic.show_string(name)
basic.show_string(“What’s her name?”)
basic.show_string(name)
basic.show_string(“Say that again?”)
basic.show_string(name)
That looks a lot cleaner, doesn’t it? We can also do the same with numbers!
basic.show_number(25)
is the same thing as
age = 25
basic.show_number(age)
Define variables before you use them!
If you ask your computer to spell your name, it must know what it is:
It also must be defined BEFORE you use them:
Sample Exercises
What should go in the question marks?
name = “Jacqui”
age = 25
basic.show_string(“My name is: “)
basic.show_string(??)
basic.show_string(“My age is: “)
basic.show_number(??)
Answer
1) name 2) age
Variables can be changed
name = “Jacqui”
name = “Drshika”
basic.show_string(name)
Any guesses as to what will show?
Answer
Drshika
name = “Jacqui”
basic.show_string(name)
name = “Drshika”
What about this?
Answer
Jacqui
Variables can do Math
number_one = 1
number_two = 2
basic.show_number(number_one + number_two)
Any guesses to what will show?
Answer
3
number_one = 10
number_two = 2
basic.show_number(number_one - number_two)
Answer
8
number_one = 5
number_two = 5
basic.show_number(number_one * number_two)
Answer
25
number_one = 15
number_two = 5
basic.show_number(number_one / number_two)
Answer
3