id and type
- Python course
- Beginner
- Lesson 10/116
- 4 min
Learn object identity and type with id() and type().
What is id?
Every object in Python has a unique identity. The id() function returns it:
x = 5
print(id(x)) # example: 140234567890The identity is the address of the object in memory. Two objects with the same value may have different identities. But for small integers Python shares them (interning).
The is operator checks whether two variables point to the same object by identity.
type vs isinstance
type(x) returns the type object of the variable. isinstance(x, int) returns True/False whether x is of that type.
type(5) == int # True
isinstance(5, int) # Trueisinstance also considers inheritance, so it is preferred for type checks. type is used when exact type equality is needed.
Practice Print the type
Assign 5 to x. Then print its type with print(type(x)).
Starter code
# Print the typeSample solution
x = 5
print(type(x))Expected output
<class 'int'>
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What does type(5) return?
- 5
- int
- <class 'int'> Correct answer
- integer
Explanation: type(5) returns <class 'int'>.
2 Check the type
type(x) == ____type(x) == intExplanation: type(x) == int checks the type.
3 Match the concepts
| Term | Meaning |
|---|---|
id() |
Object identity |
type() |
Type object |
isinstance() |
Inheritance-aware check |
is |
Identity comparison |