How to find type of variable in Python?

Finding the Type of Variable in Python

Python is a versatile and powerful programming language that allows developers to write efficient and effective code. However, one of the most common challenges developers face is determining the type of variable they are working with. In this article, we will explore the different ways to find the type of variable in Python, including using built-in functions, type hints, and manual checks.

Using Built-in Functions

Python has several built-in functions that can be used to determine the type of variable. Here are a few examples:

• type() function: The type() function returns the type of an object. You can use it to get the type of a variable like this: print(type(var))
• isinstance() function: The isinstance() function checks if an object is an instance of a particular class or type. You can use it to check if a variable is an instance of a specific type like this: print(isinstance(var, int))
• id() function: The id() function returns the unique identifier for an object. You can use it to get the type of a variable like this: print(id(var))

Here’s an example of how you can use these functions to determine the type of a variable:

# Define a variable

var = 10



# Use type() function to get the type of the variable

print(type(var))  # Output: <class 'int'>



# Use isinstance() function to check if the variable is an instance of int

print(isinstance(var, int))  # Output: True



# Use id() function to get the unique identifier for the variable

print(id(var))  # Output: 123456789

Using Type Hints

Python 3.5 and later versions support type hints, which are used to specify the type of a variable. Type hints are not enforced by the Python interpreter, but they can be used by IDEs and other tools to provide better code completion and error checking.

Here’s an example of how you can use type hints to determine the type of a variable:

# Define a variable with a type hint

x: int = 10



# Use type() function to get the type of the variable

print(type(x))  # Output: <class 'int'>



# Use isinstance() function to check if the variable is an instance of int

print(isinstance(x, int))  # Output: True

Manual Checks

Manual checks can also be used to determine the type of a variable. Here are a few examples:

• Type checking: You can use type checking libraries like mypy to check the type of a variable. mypy is a static type checker for Python that can be used to check the type of a variable.
• Debugging: You can use debugging tools like pdb to set breakpoints and inspect the value of a variable. This can be useful for debugging purposes.

Here’s an example of how you can use type checking to determine the type of a variable:

# Define a variable with a type hint

x: int = 10



# Use type() function to get the type of the variable

print(type(x))  # Output: <class 'int'>



# Use isinstance() function to check if the variable is an instance of int

print(isinstance(x, int))  # Output: True

Conclusion

Finding the type of a variable in Python can be a challenging task, but there are several ways to do it. Using built-in functions like type(), isinstance(), and id() can be useful for determining the type of a variable. Type hints can also be used to specify the type of a variable, and manual checks can be used to verify the type of a variable. By using these methods, you can write more efficient and effective code in Python.

Table: Common Variable Types in Python

Variable Type	Description
int	Whole numbers, e.g. 10, 20, 30
float	Decimal numbers, e.g. 10.5, 20.25, 30.75
str	Strings, e.g. "hello", ‘hello’, "hello world"
bool	Boolean values, e.g. True, False
list	Ordered collections of values, e.g. [1, 2, 3], ["a", "b", "c"]
tuple	Ordered, immutable collections of values, e.g. (1, 2, 3), ("a", "b", "c")
dict	Unordered collections of key-value pairs, e.g. {"name": "John", "age": 30}
set	Unordered collections of unique values, e.g. {1, 2, 3}, {"a", "b", "c"}
NoneType	The absence of a value, e.g. None

Note: This table is not exhaustive, but it covers some of the most common variable types in Python.