# Lesson 1 - Variables and Data Types

• 1.1 Creating Variables

In Python, variables are created when you assign a value to it:

Examples:

x = 5
y = 10.2
z = “David”

You can check the variable data types using the print command

print(x)

1.2 Data types

Python has the following data types built-in by default

 Text Type: `str` Numeric Types: `int`, `float`, `complex` Sequence Types: `list`, `tuple` Dictionary Type: `dict` Boolean Type: bool Set Types: set,frozenset

Let’s look at some examples below

Text Type:
x = “Population”,   h
ere, x is a variable of type str

Numeric Types:
x = 10, here x is a variable of type int
x = 8.2, here x is a variable of type float
x =  3+ 4j ,  here x  is a variable of type complex

Sequence Type – List:
Names = [“John”, “David”, “Michael”]

Sequence Type – Tuple:
Signal = (“red”, “yellow”, “green”)

Dictionary Type – dict:
marks = {“Maths”:”90″, “Physics”:”85″}

Boolean:
rained = True

Set Type – set
subjects = {“Maths”,”English”,”Science”}

Set Type – frozenset
subjects = ({“Maths”,”English”,”Science”})

Know the type of a variable

x = 5
y = “John”

print(type(x))
print(type(y))

1.3 Data type casting

You can explicitly specify the data type of a variable using a method known as casting.
x = str(5)    # x will be ‘5’
y = int(5)    # y will be 5
z = float(5)  # z will be 5.0