type() and isinstance() in Python - Step-by-Step Execution

Concept Flow - type() and isinstance()

Start with a variable

↓

Use type() to get exact type

↓

Use isinstance() to check if variable is a type or subclass

↓

If True

→Do something

↓

If False

→Do something else

↓

End

First, get the variable's exact type with type(). Then, check if it matches or inherits a type using isinstance(). Based on that, decide what to do.

Execution Sample

Python

x = 5
print(type(x))
print(isinstance(x, int))
print(isinstance(x, str))

This code shows the type of x and checks if x is an int or a str.

Execution Table

Step	Action	Expression	Result	Explanation
1	Assign	x = 5	x = 5	Variable x is set to integer 5
2	Check type	type(x)	<class 'int'>	x is exactly of type int
3	Check isinstance	isinstance(x, int)	True	x is an instance of int or subclass
4	Check isinstance	isinstance(x, str)	False	x is not an instance of str or subclass

💡 All checks done, program ends

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4
x	undefined	5	5	5	5

Key Moments - 2 Insights

Why does type(x) return <class 'int'> but isinstance(x, int) returns True?

type(x) shows the exact type of x (int). isinstance(x, int) returns True because x is an instance of int or any subclass of int. They are related but used differently as shown in execution_table rows 2 and 3.

Why does isinstance(x, str) return False even though x is a number?

Because x is not an instance of str or any subclass of str. isinstance checks if x belongs to the given type or its subclasses, as seen in execution_table row 4.

Visual Quiz - 3 Questions

Look at the execution table, what is the result of type(x) at step 2?

A False

B True

C <class 'int'>

D 5

💡 Hint

Check the 'Result' column in execution_table row 2

At which step does isinstance(x, int) return True?

A Step 3

B Step 2

C Step 4

D Step 1

💡 Hint

Look at the 'Action' and 'Result' columns in execution_table row 3

If x was a string 'hello', what would isinstance(x, str) return at step 4?

A False

B True

C <class 'str'>

D Error

💡 Hint

Refer to how isinstance works in execution_table row 4 and key_moments explanation

Concept Snapshot

type(variable) returns the exact type of variable.
isinstance(variable, type) checks if variable is of that type or subclass.
Use type() to get type info.
Use isinstance() to check type safely.
isinstance() works with inheritance; type() does not.

Full Transcript

We start by assigning the value 5 to variable x. Then, we use type(x) to find out the exact type of x, which is int. Next, we check if x is an instance of int using isinstance(x, int), which returns True because x is indeed an integer. Finally, we check if x is an instance of str using isinstance(x, str), which returns False because x is not a string. This shows how type() gives the exact type, while isinstance() checks if the variable belongs to a type or its subclasses.