Avoiding temporary arrays in NumPy - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a NumPy array of zeros with shape (3, 3).

NumPy

import numpy as np
arr = np.[1]((3, 3))

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Afull

Bones

Cempty

Dzeros

Attempts:

3 left

💡 Hint

Common Mistakes

Using np.ones instead of np.zeros

Using np.empty which creates uninitialized values

The np.zeros function creates an array filled with zeros, which is useful to avoid temporary arrays when initializing.

2fill in blank

medium

Complete the code to multiply two arrays element-wise without creating a temporary array.

NumPy

import numpy as np
arr1 = np.array([1, 2, 3])
arr2 = np.array([4, 5, 6])
result = np.multiply(arr1, arr2, out=[1])

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Aarr1

BNone

Carr2

Dresult

Attempts:

3 left

💡 Hint

Common Mistakes

Setting out to None creates a new array (temporary)

Setting out to a variable not defined yet

Using the out parameter with arr1 stores the result directly in arr1, avoiding a temporary array.

3fill in blank

hard

Fix the error in the code to add 5 to each element of arr without creating a temporary array.

NumPy

import numpy as np
arr = np.array([1, 2, 3])
np.add(arr, [1], out=arr)

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Aarr

Bnp.array([5,5,5])

C5

Dnp.add

Attempts:

3 left

💡 Hint

Common Mistakes

Using arr = arr + 5 creates a temporary array

Using np.add without out parameter

Adding a scalar like 5 creates a temporary array. To avoid this, use the out parameter or in-place addition.

4fill in blank

hard

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

NumPy

words = ['apple', 'bat', 'carrot', 'dog']
lengths = { [1]: [2] for word in words if len(word) > 3 }

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Aword

Blen(word)

Cword.upper()

Dlen(word) > 3

Attempts:

3 left

💡 Hint

Common Mistakes

Using the condition as a key or value

Using word.upper() instead of word as key

The dictionary comprehension uses the word as the key and its length as the value, filtering words longer than 3 characters.

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 3.

NumPy

words = ['apple', 'bat', 'carrot', 'dog']
lengths = { [1]: [2] for word in words if len(word) [3] 3 }

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

Aword.upper()

Blen(word)

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using < instead of > in the condition

Using word instead of word.upper() as key

The comprehension maps uppercase words to their lengths, filtering words with length greater than 3.