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 =.
- Different most used primitive data types in Python are integer, string, float, and boolean.
# 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
# re - declare variables student = 200 print(student) student = "James" # re - declare variable print(student)
- In Python, we cannot concatenate different types of variables.
- 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