In this tutorial we are going to learn :
- Variables in Python
- Variable Name’s Rules
- Creating Variables
- Re – Declare Variables
- Concatenate Variables
Variables in Python
- Variable is a named location for storing data values.
- Unlike many other programming languages, variables don’t need to be declared any particular type.
- Every value in Python has a different data type. Different primitive data types in Python are integer, string, float, boolean, etc.
Variable Names Rules
- A variable name must start with a letter(either upper or lower case ) or an underscore _ character.
- They can contain numbers, letters or underscore characters but (cannot begin
with a number. - Variable names are case-sensitive (student_number, Student_number, STUDENT_NUMBER are three different variables).
- Variables are created when they are first attached to a value, using =.
Creating Variables
- Different most used primitive data types in Python are integer, string, float, and boolean.
Example :
# creating variables
student_numbers = 200 # integer
product_name = "Computer" # string
number = 12.9 # float
is_right = True # boolean
#printing variables
print(student_numbers)
print(product_name)
print(number)
print(is_right) 
Re – Declare Variables
- We can also change variables after we create and declare them
Example :
# re - declare variables
student = 200
print(student)
student = "James" # re - declare variable
print(student) 
Concatenate Variables
- In Python, we cannot concatenate different types of variables.
Example :
- Correct Uses of Concatenate Variables.
We used the str() function to convert int to string. so we can concatenate them.
# Concatenate Variables
first_number = 10
second_number = 20
age = 21
name = "James"
comment = "Awesome"
# Correct uses - Concatenate Variables
print(first_number + second_number) # int + int
print("Python is " + comment) # string + string
print(name + " is " + str(age) + " years old. ") # String + int 
