Built-in Functions

The Python interpreter has a number of functions and types built into it that are always available.

Built-in Functions

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See also:

Built-in Functions - Python 3.12.1 documentation

Built-in Sequence Functions

Key Terms

True/False (Mark T for True and F for False)

Answer Key (True/False):

Multiple Choice (Select the best answer)

Answer key (Mutiple Choice):

What is the output of the following Python code?

numbers = [10, 32, 98, 38, 47, 34] print(max(numbers))

- **A.** 10 
- **B.** 32 
- **C.** 98 
- **D.** 38

Watch this video for the answer: https://youtube.com/shorts/x7zh_WqO1e4

What is the output of the following code? [Python Quiz #11]

def my_func(fruit):
    if fruit:
        return  True
    return  False

fruits = ["apple","", "orange"
,"mango" ]

print(list(filter(my_func,fruits)))
```python

**A)** ['apple', 'orange', 'mango']
**B)** ['apple', '', 'orange', 'mango']
**C)** ['', '', '']
**D)** ['True', 'False', 'True', 'True']

**Watch this video for the answer:** [https://youtube.com/shorts/gkGpJfxsDew](https://youtube.com/shorts/gkGpJfxsDew)

#43 What is the output of the zip() function when one iterable is shorter than the others?

Watch the Video Tutorial for the Answer: https://youtube.com/shorts/TOxTxP9x4ME?feature=share

#python #pythonpoll #MCQsTest #yasirbhutta

a) The function raises an exception
b) The function returns only the tuples that have corresponding elements in all iterables
c) The function pads the shorter iterable with None values
d) The function pads the shorter iterable with the last value of the iterable

Answer: b) The function returns only the tuples that have corresponding elements in all iterables

#42 What does the zip() function in Python do?

Watch the Video Tutorial for the Answer: https://youtube.com/shorts/7ix3cDWAsUc?feature=share

#python #pythonpoll #MCQsTest #yasirbhutta

### MCQs: Iterators and `zip()` in Python

#### **Question 1**  

What is the output of the following code?  

```python
list_a = [1, 2, 3]
list_b = ['x', 'y', 'z']
zipped = zip(list_a, list_b)

print(list(zipped))
print(list(zipped))

[(1, 'x'), (2, 'y'), (3, 'z')]
[(1, 'x'), (2, 'y'), (3, 'z')]

[(1, 'x'), (2, 'y'), (3, 'z')]
[]

[]
[]

Error: zip object has already been used.

Correct Answer: B

for more details, see Appendix A: Exploring the One-Time Use Behavior of zip() and Iterators in Python

Question 2

Why does the second print(list(zipped)) in the following code output an empty list?

list_a = [1, 2, 3]
list_b = ['x', 'y', 'z']
zipped = zip(list_a, list_b)

print(list(zipped))
print(list(zipped))

A) The zip object is immutable.
B) The zip object is an iterator, and it can be consumed only once.
C) The zip object is reset after every list() call.
D) The zip object contains only one item by default.

Correct Answer: B

for more details, see Appendix A: Exploring the One-Time Use Behavior of zip() and Iterators in Python

Question 4

What does the zip() function return in Python?

A) A tuple of paired elements.
B) A dictionary mapping keys from the first list to values from the second list.
C) An iterator that pairs elements from the input iterables.
D) A list of tuples pairing elements from the input iterables.

Correct Answer: C

a) Compresses a file into a ZIP archive b) Combines two or more iterables into a single iterable of tuples, where each tuple contains one element from each iterable c) Creates a dictionary from two iterables, with keys from one iterable and values from another iterable d) Calculates the checksum of a file

Answer: b) Combines two or more iterables into a single iterable of tuples, where each tuple contains one element from each iterable

Q: What is the syntax for the zip() function in Python? a) zip(iterable1, iterable2) b) zip(iterable1, iterable2, …) c) zip(*iterables) d) zip(iterables)

Answer: c) zip(*iterables)

Q: How can you use the zip() function to unzip a list of tuples? a) list(zip(tuples_list)) b) tuple(zip(tuples_list)) c) set(zip(tuples_list)) d) dict(zip(tuples_list))

Answer: a) list(zip(*tuples_list))

Fill in the Blanks

Answer Key (Fill in the Blanks):

Exercises

Review Questions

References and Bibliography

[1]“Built-in Functions — Python 3.12.4 documentation,” docs.python.org. https://docs.python.org/3/library/functions.html ‌

Appendices

Appendix A: Exploring the One-Time Use Behavior of `zip()` and Iterators in Python

The behavior you’re observing is due to the fact that zip() returns an iterator, not a list. Iterators in Python are designed to be consumed as they are iterated over. Once an iterator is exhausted, it cannot be reused.

Step-by-step Explanation:

First list(zipped_lists):
- The zip object (zipped_lists) is converted to a list.
- During this process, the iterator is consumed, meaning all pairs are retrieved and stored in the resulting list: [(1, 'a'), (2, 'b'), (3, 'c')].
Second list(zipped_lists):
- At this point, the zip object (zipped_lists) has already been fully consumed in the first list() call.
- Since there are no more elements left in the iterator, the second call returns an empty list: [].

How to Fix It:

If you need to reuse the results of zip, you can:

Convert to a list immediately:

zipped_lists = list(zip(list_a, list_b))
print(zipped_lists)
print(zipped_lists)

Output:

[(1, 'a'), (2, 'b'), (3, 'c')]
[(1, 'a'), (2, 'b'), (3, 'c')]

Create a new zip object each time:

list_a = [1, 2, 3]
list_b = ['a', 'b', 'c']
print(list(zip(list_a, list_b)))
print(list(zip(list_a, list_b)))

Output:

[(1, 'a'), (2, 'b'), (3, 'c')]
[(1, 'a'), (2, 'b'), (3, 'c')]

This ensures you always have a fresh iterator to work with.

Built-in Functions