How variable type changes at runtime in Python - Quick Revision & Summary

Recall & Review

beginner

What does it mean that Python variables can change type at runtime?

It means a variable can hold a value of one type at one moment, and later hold a value of a different type without errors.

beginner

Show an example where a variable changes from an integer to a string.

x = 5 # x is an integer x = "hello" # now x is a string

intermediate

Why can Python variables change type at runtime?

Because Python uses dynamic typing, it does not fix variable types when you write code. Types are checked when the program runs.

beginner

What happens if you try to use a variable in a way that doesn't match its current type?

Python will raise an error if the operation is not supported for the variable's current type.

beginner

Can you assign a list to a variable that was previously an integer? Why?

Yes, because Python variables are just names pointing to values. You can assign any type of value to the same variable name.

What type does a Python variable have?

A A fixed type set when the variable is created

B Always string

C The type of the value it currently holds

D Always integer

Python variables have the type of the value they currently hold, not a fixed type.

What happens if you assign a string to a variable that was holding an integer?

A The variable changes to hold the string

B Python gives a syntax error

C The variable keeps the integer value

D The program crashes immediately

Python allows variables to change type by assigning a new value of a different type.

Which typing system allows variables to change type at runtime?

A Static typing

B Dynamic typing

C Strong typing

D Weak typing

Dynamic typing means types are checked at runtime and variables can change type.

If x = 10, then x = 'ten', what is the type of x now?

A boolean

B integer

C float

D string

After assigning 'ten', x holds a string value.

What error occurs if you try to add a number and a string in Python?

A TypeError

B SyntaxError

C NameError

D ValueError

Python raises a TypeError when you try to perform unsupported operations between incompatible types.

Explain how Python variables can change their type during program execution.

Think about how Python treats variable names and values.

Give an example where a variable changes from one type to another and explain what happens.

Use simple types like integer and string.