How variable type changes at runtime in Python - Practice Exercises

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of variable type changes?

Consider the following Python code where a variable changes its type during execution. What will be printed?

Python

x = 10
print(type(x))
x = 'hello'
print(type(x))

A <class 'int'>\n<class 'str'>

B <class 'str'>\n<class 'int'>

C <class 'int'>\n<class 'int'>

D TypeError

💡 Hint

Remember that Python variables can hold values of any type and can change types anytime.

Initially, x is assigned an integer 10, so type(x) is int. Then x is assigned a string 'hello', so type(x) becomes str.

❓ Predict Output

intermediate

What is the final type of variable after reassignment?

Look at this code where a variable is reassigned multiple times. What is the type of variable 'data' at the end?

Python

data = 3.14
print(type(data))
data = [1, 2, 3]
print(type(data))
data = {'a': 1}
print(type(data))

A <class 'int'>\n<class 'list'>\n<class 'dict'>

B <class 'float'>\n<class 'dict'>\n<class 'list'>

C <class 'float'>\n<class 'list'>\n<class 'dict'>

D SyntaxError

💡 Hint

Check the type after each assignment carefully.

The variable 'data' first holds a float, then a list, then a dictionary. Each print shows the current type.

❓ Predict Output

advanced

What is the output when variable type changes inside a function?

What will this code print when a variable changes type inside a function?

Python

def change_var():
    var = 5
    print(type(var))
    var = 'changed'
    print(type(var))

change_var()

A <class 'str'>\n<class 'int'>

B <class 'int'>\n<class 'int'>

C NameError

D <class 'int'>\n<class 'str'>

💡 Hint

Variables inside functions behave the same way as outside in terms of type changes.

Inside the function, var starts as int, then changes to str. Both types print accordingly.

❓ Predict Output

advanced

What error occurs when using variable before assignment after type change?

What error will this code raise when a variable is used before assignment after changing its type?

Python

x = 10
print(x)
x = x + '5'
print(x)

A SyntaxError

B TypeError

C NameError

D No error, prints 15

💡 Hint

Think about what happens when you add an integer and a string.

Adding int and str causes a TypeError because Python cannot combine these types directly.

🧠 Conceptual

expert

How does Python handle variable types at runtime?

Which statement best describes how Python handles variable types during program execution?

A Python variables are dynamically typed and can change type when assigned new values.

B Python requires explicit type declarations before assigning values.

C Python variables have fixed types assigned at declaration and cannot change.

D Python variables are statically typed and checked at compile time.

💡 Hint

Think about how you can assign different types to the same variable name in Python.

Python is dynamically typed, meaning variables can hold any type and change type during execution.