Python Variables
A variable is a name which is used to reserve space in memory for storing values.
A variable in Python is created when we assign a value to it.
Here's an example where "name," "contact_number," "amount," and "status" are variables in which we can store values:
name = "Danny"
contact_number = 987654
amount = 150.60
status = True
print(name)
print(contact_number)
print(amount)
print(status)
The output of the above code is as follows:
Danny 987654 150.6 True
Dynamically Typed Programming Language
Python is dynamically typed programming language, meaning we do not need to declare the data type of a variable. The type of a variable can also be changed by reassigning a new value of another type to already declared variable.
Here's an example to demonstrate this:
name = "Danny"
name = 123456
print(name)
The output of the above code is as follows:
123456
How to name a variable?
Use small letters and in case of multiple words, separate words with underscore to improve readability.
Here are some good examples of variable names:
first_name = "Danny"
last_name = "Lee"
phone_number = "+1234567890"
email = "danny@tutorialsbuddy.com"
designation = "Python Engineer"
price = 107.45
is_active = True
Variables are Case-Sensitive
In Python, variables are case-sensitive. A variable name a and A are not same but two different variables.
Here's an example to demonstrate this:
a = "Hello"
A = 17
print(a)
print(A)
The output of the above code is as follows:
Hello 17
How to find the data type of a variable?
To find the data type of a variable, use type() built-in function of Python.
Here's an example to demonstrate this:
first_name = "Danny"
price = 107.45
is_active = True
print(type(first_name))
print(type(price))
print(type(is_active))
The output of the above code is as follows:
<class 'str'> <class 'float'> <class 'bool'>
To determine whether a variable is of a specific type, use isinstance() function:
x = "Python"
y = 10
z = True
print(isinstance(x,str))
print(isinstance(y,bool))
print(isinstance(z,bool))
The output of the above code is as follows:
True False True