2_variables.py

# ** Variables ** 
# 
# A variable is a way of storing a piece of data or information for reuse. In
# Python, variables are assigned using the equals sign `=`. For example, the 
# following line: 
x = 1
# assigns the value 1 to the variable x. 
# 
# When a variable name is multiple words long, the words are separated with
# underscores, like so: 

my_long_variable_name = 1

# ** Data types ** 
#
# In Python, variables can contain many different types of data. Here are some
# examples. 
# 
# An integer is a whole number. 
my_integer = 1 
# A float is a number with a decimal point.
my_float = 1.1 
# A string is a piece of text. Strings are surrounded by either single or 
# double quotes. 
my_string = "Hello, world!" 
my_other_string = 'Hello, students!'
# A boolean is a special data type that can take on only one of two binary 
# values: True or False 
my_positive_boolean = True
my_negative_boolean = False

# ** Exercises ** 
# 1. Variables can be reused. On line 38, set y to a new value. Then run 
# the code to see the output. Note: you can print multiple things at once
# by separating them with a comma! 

y = 0
print("y =", y)
# Your code here (give y a new value)
print("y is different now!")
print("y =", y)

# 2. What happens when you have an error in your code? Let's find out! 
#    Uncomment the line below and see what happens. 
#print(Oops, I tried to print a string without parentheses!)
#    Inspect the error message closely.  What information does it give you? 
#    Learning how to read error messages will be important for debugging later!