Variables are nothing but reserved memory locations to store values. This means that when you create a variable you reserve some space in memory. Variable also known as identifier and used to hold value.
In Python, we don’t need to specify the type of variable, because Python is language and smart enough to get variable type.
How to define Variable Names
A variable can have a short name (like x and y) or a more descriptive name (age, carname, total_volume). Rules for Python variables:
- A variable name must start with a letter or the underscore character
- A variable name cannot start with a number
- A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
- Variable names are case-sensitive (age, Age and AGE are three different variables)
Declaring Variable and Assigning Values
Python allows us to create variable at required time. It does not bound us to declare variable before using in the application. We don’t need to declare explicitly variable in Python. When we assign any value to the variable that variable is declared automatically.
The equal (=) operator is used to assign value to a variable.
counter = 100 # An integer assignment
miles = 1000.0 # A floating point
name = “John” # A string
Here, 100, 1000.0 and “John” are the values assigned to counter, miles, and name variables, respectively.
Python allows us to assign a value to multiple variables in a single statement which is also known as multiple assignments. We can apply multiple assignments in two ways either by assigning a single value to multiple variables or assigning multiple values to multiple variables. Lets see given examples.
X = Y = Z = 50
Let’s explore above concept through jupyter notebook