Python Interview Essentials Quiz Quiz

Test your Python knowledge with 15 easy and essential Python interview questions. Perfect for beginners preparing for Python interviews and those wanting to strengthen their Python programming basics.

1. Python Data Types

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

   1. List
   2. Set
   3. Dictionary
   4. Tuple

   Explanation: Tuples in Python are immutable, meaning once created, their elements cannot be changed. Lists and dictionaries are mutable, so their contents can be modified. Sets are mutable as well, which allows elements to be added or removed.

2. Python Variables

   What is the correct way to assign the value 5 to a variable named x in Python?

   1. x: 5
   2. x u003C- 5
   3. x = 5
   4. int x = 5

   Explanation: In Python, you assign a value to a variable using the equals sign, as in x = 5. The u003C- operator is not used in Python, int x = 5 is Java or C-style syntax, and x: 5 is invalid in this context.

3. Indentation Importance

   Why is indentation important in Python?

   1. It makes code faster
   2. It defines code blocks
   3. It adds comments to code
   4. It improves code readability

   Explanation: Indentation in Python is used to define code blocks, such as those in functions or loops. While indentation can improve readability, its primary role in Python is syntactical. Indentation does not affect code execution speed or function as comments.

4. String Concatenation

   What will be the output of 'Hello' + ' ' + 'World' in Python?

   1. Hello+World
   2. Hello World
   3. HelloWorld
   4. Hello, World

   Explanation: Concatenating 'Hello', a space character, and 'World' results in 'Hello World'. 'HelloWorld' lacks the space, 'Hello+World' adds a plus sign, and 'Hello, World' introduces a comma not present in the original strings.

5. Python Comments

   Which symbol is used to write a single-line comment in Python?

   1. u003C!--
   2. //
   3. #
   4. /*

   Explanation: The hash symbol (#) is used for single-line comments in Python. Double slashes (//) are used in languages like JavaScript or Java, /* and u003C!-- are not used for this purpose in Python.

6. Loop Structures

   Which statement is used to iterate over a sequence in Python?

   1. for
   2. loop
   3. repeat
   4. switch

   Explanation: The 'for' statement is used to loop over sequences such as lists or strings in Python. Python does not have a 'loop' or 'repeat' keyword, and 'switch' is used in other languages for selection, not iteration.

7. Function Definition

   How do you define a function named hello in Python?

   1. function hello():
   2. fun hello():
   3. def hello():
   4. hello func():

   Explanation: Functions in Python are defined using the 'def' keyword, followed by the function name and parentheses. The other options use incorrect keywords or structure not recognized in Python.

8. Range Function Output

   What does list(range(3)) return in Python?

   1. [0, 1, 2, 3]
   2. [1, 2, 3]
   3. [1, 2]
   4. [0, 1, 2]

   Explanation: list(range(3)) gives a list of numbers starting from 0 up to, but not including, 3: [0, 1, 2]. The [1, 2, 3] option starts from 1 and is incorrect, [0, 1, 2, 3] goes one too far, and [1, 2] is too short.

9. Type Conversion

   Which function converts a string to an integer in Python?

   1. input()
   2. str()
   3. int()
   4. float()

   Explanation: The int() function converts a string to an integer if the string contains numeric characters. float() converts to a floating-point number, str() makes the input a string, and input() is used for user input.

10. List Comprehension

    Which of the following uses list comprehension to create a list of squares of numbers from 0 to 4?

    1. [x**2 where x in range(5)]
    2. [x*x for x in range(5)]
    3. [x^2 for x in range(5)]
    4. [square(x) for x in 0..4]

    Explanation: [x*x for x in range(5)] correctly computes the square of each number using list comprehension in Python. The first uses '^' which performs bitwise XOR, not exponentiation. The third is syntactically incorrect, and the fourth uses an undefined square function and an invalid range.

11. Python Dictionaries

    Which method would you use to get all keys from a Python dictionary named mydict?

    1. mydict.getKeys()
    2. mydict.allKeys()
    3. mydict.items()
    4. mydict.keys()

    Explanation: mydict.keys() returns a view object of all keys in the dictionary. mydict.getKeys() and mydict.allKeys() are not valid methods, while mydict.items() returns both keys and values.

12. None Keyword

    What does the 'None' keyword represent in Python?

    1. An empty string
    2. A zero value
    3. A null value
    4. A false statement

    Explanation: 'None' is Python’s way of representing the absence of a value, similar to 'null' in other languages. It is not the same as zero or an empty string, and it does not represent False, even though it's considered False in a Boolean context.

13. Exception Handling

    Which keywords are used for error handling in Python?

    1. switch and case
    2. begin and rescue
    3. do and catch
    4. try and except

    Explanation: try and except blocks are used in Python to handle errors and exceptions. begin and rescue are used in Ruby, do and catch are from other languages, and switch and case are used for selection, not exception handling.

14. Boolean Evaluation

    What is the output of bool([]) in Python?

    1. None
    2. False
    3. Error
    4. True

    Explanation: An empty list evaluates to False when passed to the bool() function in Python. Non-empty containers evaluate to True, so True is incorrect. Error and None are not produced here.

15. Getting List Length

    Which function returns the number of elements in a list named items?

    1. size(items)
    2. count(items)
    3. len(items)
    4. length(items)

    Explanation: The len() function is used in Python to retrieve the number of elements in a list or other container. count(items) is not correct (though count is a list method for counting occurrences of a specific element), and size(items) and length(items) are not built-in Python functions.

16. Default Parameter

    How can you specify a default parameter value in a Python function?

    1. By omitting the parameter entirely
    2. By assigning value in the function call
    3. By using default = value in function body
    4. By setting parameter=value in the definition

    Explanation: Default parameter values in Python functions are set by providing parameter=value in the function definition. Assigning value elsewhere or using 'default =' syntax is not correct, and simply omitting the parameter does not set a default.