Indexing returns views not copies in NumPy - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a view of the first three elements of the array.

NumPy

import numpy as np
arr = np.array([1, 2, 3, 4, 5])
view = arr[1]

Drag options to blanks, or click blank then click option'

A[0,3]

B(0:3)

C[0:3]

D[0-3]

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses instead of square brackets for slicing.

Using commas inside the brackets which is for indexing multiple dimensions.

Using subtraction inside the brackets which is invalid syntax.

The slice [0:3] creates a view of the first three elements of the array.

2fill in blank

medium

Complete the code to modify the view and show it affects the original array.

NumPy

import numpy as np
arr = np.array([10, 20, 30, 40, 50])
view = arr[1:4]
view[1] = 99
result = arr

Drag options to blanks, or click blank then click option'

A[1]

B[0]

C[2]

D[3]

Attempts:

3 left

💡 Hint

Common Mistakes

Modifying an index outside the view's range causing an error.

Assuming the view is a copy and changes won't affect the original array.

Changing view[1] modifies the second element of the view, which corresponds to arr[2]. This change affects the original array because the view shares data.

3fill in blank

hard

Fix the error in the code to create a view of the last two elements.

NumPy

import numpy as np
arr = np.array([5, 10, 15, 20, 25])
view = arr[1]

Drag options to blanks, or click blank then click option'

A[-2:]

B[-2]

C[-2::-1]

D[-2;]

Attempts:

3 left

💡 Hint

Common Mistakes

Using a single index instead of a slice.

Using invalid slice syntax like semicolons.

The slice [-2:] correctly selects the last two elements as a view. Using [-2] selects a single element, not a slice.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps words to their lengths only if length is greater than 3.

NumPy

words = ['data', 'is', 'fun', 'science']
lengths = {word: [1] for word in words if [2]

Drag options to blanks, or click blank then click option'

Alen(word)

Blen(word) > 3

Clen(word) < 3

Dword

Attempts:

3 left

💡 Hint

Common Mistakes

Using the word itself as the value instead of its length.

Using the wrong condition to filter words.

The dictionary comprehension uses len(word) to get the length and filters words with length greater than 3 using len(word) > 3.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps uppercase words to their lengths only if length is greater than 2.

NumPy

words = ['apple', 'is', 'red', 'big']
result = [1]: [2] for w in words if [3]

Drag options to blanks, or click blank then click option'

Aw.upper()

Blen(w)

Clen(w) > 2

Dw.lower()

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase instead of uppercase for keys.

Not filtering words by length correctly.

The dictionary comprehension maps the uppercase version of each word (w.upper()) to its length (len(w)) only if the length is greater than 2 (len(w) > 2).