Variables and Data Types
What is a Variable
A Python variable is a reserved memory location to store values in other words a variables are containers for storing data values.
Declaring a variable
Python has no command for declaring a variable. When you initially assign a value to a variable, it is said to be created. Variables do not need to be defined with a specific type, and they can even change types after being set.
age = 7 # i have assigned 7 to a variable called age thus the value of age is 7 name = "john" # i have assigned john to a variable called name thus the value of name is John
Variables do not need to be declared with any particular type, and can even change type after they have been set.
y = 7 # variable y created with the value 7 and since 7 is an integer thus variable y is of type integer y = "paul" # variable y created earlier has been assigned paul as its values and its a string thus y is of type string
Python Data Types
Data type is an important concept in programming. Variables can store a variety of data, and different types can perform different tasks. These are the basic type of data types
age = 7 # int elevy = 1.5 # float name = "John" # str using a double quote name = 'Paul' # str using a single quote is_active = True # bool
Every value in Python has a datatype. Different data types in Python are Numbers, List, Tuple, Strings, Dictionary, etc. and these data types, which are built-in by default, can be categories as follows:
Text Type: str Numeric Types: int, float, complex Sequence Types: list, tuple, range Mapping Type: dict Set Types: set, frozenset Boolean Type: bool Binary Types: bytes, bytearray, memoryview None Type: NoneType
- Variables names are case sensitive (age and Age are different variables
- Variables must start with a letter or an underscore
- Variables can have numbers but cannot start with one
Type Casting is the process of converting a literal of one type to another in Python. For typecasting, utilize the built-in functions int (), float (), and str (). int () accepts a float or string literal as an argument and returns an int value.
age = "7" age = int(age) # converting age of string 7 to integer 7 age = 7 age = str(age) $ converting age of integer 7 to string 7
Casting can be used to specify the data type of a variable.
x = str(3) # x will be '3' y = int(3) # y will be 3 z = float(3) # z will be 3.0
Get the Type
The type() method returns the data type of a variable.
age = 5 name = "John" print(type(age)) print(type(name))
Python is case sensitive when it comes to variable names.
a = 17 A = "John" NB: A will not overwrite a, A and a are two different variables
Python allows you to assign a single value to several variables simultaneously. Y
# Example 1 # An integer object is created with the value 1, and all three variables are assigned to the same memory location. a = b = c = 1
you can also assign multiple objects to multiple variables as follows:
name, age, school, class, is_girl = ("sally", 7, "St Paul International", "pinky class", True)