Strides and how data is accessed in NumPy - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a 2D NumPy array with shape (3, 4).

NumPy

import numpy as np
arr = np.array([1])
print(arr.shape)

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

A[[1, 2, 3], [4, 5, 6]]

B[[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]]

C[[1, 2], [3, 4], [5, 6]]

D[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]

Attempts:

3 left

💡 Hint

Common Mistakes

Using a flat list instead of a list of lists.

Creating inner lists with wrong length.

The array must be a list of lists to create a 2D array with shape (3, 4). Option B matches this shape.

2fill in blank

medium

Complete the code to get the strides of the NumPy array 'arr'.

NumPy

import numpy as np
arr = np.array([[1, 2], [3, 4], [5, 6]])
strides = arr.[1]
print(strides)

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

Astrides

Bdtype

Cshape

Dsize

Attempts:

3 left

💡 Hint

Common Mistakes

Using shape instead of strides.

Trying to call a method instead of accessing an attribute.

The strides attribute shows how many bytes to step in each dimension when traversing the array.

3fill in blank

hard

Fix the error in the code to correctly reshape the array without copying data.

NumPy

import numpy as np
arr = np.arange(6)
reshaped = arr.[1]((2, 3), order='C')
print(reshaped)

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

Areshape

Bresize

Cflatten

Dravel

Attempts:

3 left

💡 Hint

Common Mistakes

Using resize which modifies the array in-place.

Using flatten or ravel which change the array to 1D.

The reshape method returns a new view or copy with the new shape without changing the original data layout.

4fill in blank

hard

Fill both blanks to create a transposed view of the array and print its strides.

NumPy

import numpy as np
arr = np.array([[1, 2, 3], [4, 5, 6]])
transposed = arr.[1]
print(transposed.[2])

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

AT

Bshape

Cstrides

Dtranspose

Attempts:

3 left

💡 Hint

Common Mistakes

Using transpose() as a method call instead of property T.

Printing shape instead of strides.

T is a property that returns the transposed view of the array. The strides attribute shows how data is accessed in memory.

5fill in blank

hard

Fill all three blanks to create a dictionary of word lengths for words longer than 3 characters.

NumPy

words = ['data', 'science', 'is', 'fun']
lengths = { [1]: [2] for word in words if len(word) [3] 3 }

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

Aword

Blen(word)

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using the length as key and word as value.

Using '<' instead of '>' in the condition.

The dictionary comprehension uses the word as key, length as value, and filters words with length greater than 3.