np.sum() and axis parameter in NumPy - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to calculate the sum of all elements in the array.

NumPy

import numpy as np
arr = np.array([1, 2, 3, 4])
total = np.sum([1])
print(total)

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Asum

Bnp

Carr

D[1, 2, 3, 4]

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the module name 'np' instead of the array.

Passing the function name 'sum' instead of the array.

Passing a list literal instead of the array variable.

We use np.sum(arr) to add all elements in the array arr.

2fill in blank

medium

Complete the code to calculate the sum of each column in the 2D array.

NumPy

import numpy as np
arr = np.array([[1, 2], [3, 4]])
sums = np.sum(arr, axis=[1])
print(sums)

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A-1

B1

C2

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using axis=1 to sum columns instead of rows.

Using an invalid axis number.

Omitting the axis parameter.

Using axis=1 sums across columns for each row, giving the sum of each row's elements.

But since we want the sum of each column, we use axis=0.

However, the question asks for sum of each column, so the correct axis is 0.

3fill in blank

hard

Fix the error in the code to sum each row in the 2D array.

NumPy

import numpy as np
arr = np.array([[5, 6, 7], [8, 9, 10]])
sums = np.sum(arr, axis=[1])
print(sums)

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A1

B2

C0

D-1

Attempts:

3 left

💡 Hint

Common Mistakes

Using axis=0 to sum rows instead of columns.

Using an axis value that is out of range.

To sum each row, we sum across columns, which is axis=1.

4fill in blank

hard

Fill both blanks to create a dictionary with words as keys and their lengths as values, but only for words longer than 3 letters.

NumPy

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

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Alen(word)

B>

C<

Dword

Attempts:

3 left

💡 Hint

Common Mistakes

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

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

The dictionary comprehension uses len(word) to get the length, and the condition len(word) > 3 to filter words longer than 3 letters.

5fill in blank

hard

Fill all three blanks to create a dictionary with uppercase words as keys and their lengths as values, but only for words longer than 3 letters.

NumPy

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

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Aword.upper()

Blen(word)

C>

Dword

Attempts:

3 left

💡 Hint

Common Mistakes

Using the original word instead of uppercase for keys.

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

Using word instead of len(word) for values.

The dictionary comprehension uses word.upper() as keys, len(word) as values, and filters words with length greater than 3 using >.