Python Variables and Data Types

Questions and Answers

How do you declare a variable in Python?

C.int x = 10

B.x = 10

x = 10 (correct)

var x = 10

Which of the following creates a set in Python?

A.set = []

B.set = {}

C.set = set() (correct)

D.set =

What is the output of the following code: x = {1, 2, 3}; x.add(4); print(x)

Error

{1, 2, 3}

{1, 2, 3, 4} (correct)

{1, 4, 2, 3}

How do you declare a constant variable in Python?

D.X = 10 Signup and view all the answers

What is the output of the following code: x = 10; y = 20; print(x == y)

False Signup and view all the answers

How do you convert a string to an integer in Python?

A.int('10') Signup and view all the answers

What is the correct syntax to create a variable in Python?

x = 5 Signup and view all the answers

What is the output of the following code? x = 5; y = "5"; print(x + y)

TypeError Signup and view all the answers

How do you create a list in Python?

list = [] Signup and view all the answers

What is the keyword used to define a function in Python?

def Signup and view all the answers

Which of the following is a mutable data type in Python?

list Signup and view all the answers

What is the output of the following code? x = (1, 2, 3); x = 10; print(x)

10 Signup and view all the answers

Which of the following is an immutable data type in Python?

str Signup and view all the answers

Study Notes

Variables and Data Types

In Python, a variable is created by assigning a value to a name using the assignment operator (=).
The correct syntax to create a variable in Python is x = 5.

Data Types

Integer data type in Python: C. 42.
The output of type(3.14) is float.
A valid variable name in Python cannot start with a number, so A. 3dogs is not valid.
The output of print(type(x)) where x = "Hello" is str.
Mutable data type in Python: D. list.
The keyword used to define a function in Python is B. def.
The keyword used to create a class in Python is B. class.

List

A list in Python is created using square brackets [].
The output of print(type(x) == int) where x = 5 is True.
An immutable data type in Python: C. str.
The output of print(x) where x = [1, 2, 3] and then x = 10 is 10.

Dictionary

A dictionary in Python is created using curly brackets {}.
The output of print(x) where x = (1, 2, 3) and then x = 10 is 10.

Boolean

A boolean data type in Python: C. True.

Sets

A set in Python is created using the set() function.
The output of print(x) where x = {1, 2, 3} and then x.add(4) is {1, 2, 3, 4}.

Tuples

A tuple in Python is created using parentheses ().
The output of print(x + y) where x = (1, 2, 3) and y = (4, 5, 6) is (1, 2, 3, 4, 5, 6).

Constants

There is no specific way to declare a constant variable in Python, but by convention, constants are written in uppercase letters, such as X = 10.

Operations

The output of print(x + y) where x = 5 and y = "5" is TypeError.
The output of print(x == y) where x = 10 and y = 20 is False.

Conversions

The correct way to convert a string to an integer in Python is A. int("10").