np.vstack() and np.hstack() in NumPy - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to stack arrays vertically using numpy.

NumPy

import numpy as np

arr1 = np.array([1, 2, 3])
arr2 = np.array([4, 5, 6])
result = np.[1]([arr1, arr2])
print(result)

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

Ahstack

Bvstack

Cconcatenate

Dstack

Attempts:

3 left

💡 Hint

Common Mistakes

Using np.hstack() which stacks arrays horizontally.

Using np.concatenate() without specifying axis.

Using np.stack() which requires axis argument.

np.vstack() stacks arrays vertically (row-wise), creating a 2D array with arr1 and arr2 as rows.

2fill in blank

medium

Complete the code to stack arrays horizontally using numpy.

NumPy

import numpy as np

arr1 = np.array([1, 2, 3])
arr2 = np.array([4, 5, 6])
result = np.[1]([arr1, arr2])
print(result)

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

Aconcatenate

Bvstack

Chstack

Dstack

Attempts:

3 left

💡 Hint

Common Mistakes

Using np.vstack() which stacks arrays vertically.

Using np.concatenate() without specifying axis.

Using np.stack() which requires axis argument.

np.hstack() stacks arrays horizontally (column-wise), joining arr1 and arr2 side by side.

3fill in blank

hard

Fix the error in the code to stack two 2D arrays vertically.

NumPy

import numpy as np

arr1 = np.array([[1, 2], [3, 4]])
arr2 = np.array([[5, 6]])
result = np.[1]([arr1, arr2])
print(result)

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

Ahstack

Bconcatenate

Cstack

Dvstack

Attempts:

3 left

💡 Hint

Common Mistakes

Using np.hstack() which requires matching row counts.

Using np.concatenate() without axis=0.

Using np.stack() without axis argument.

np.vstack() stacks arrays vertically. Here arr2 has one row, so vertical stacking works.

4fill in blank

hard

Fill both blanks to create a dictionary of word lengths for words longer than 3 letters.

NumPy

words = ['cat', 'house', 'dog', 'elephant']
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 word instead of len(word) for value.

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

Not filtering words by length.

We use len(word) to get length and filter words with length greater than 3.

5fill in blank

hard

Fill all three blanks to create a dictionary with uppercase keys and values greater than 0.

NumPy

data = {'a': 1, 'b': -2, 'c': 3}
result = { [1]: [2] for k, v in data.items() if v [3] 0 }
print(result)

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Ak.upper()

Bv

C>

Dk

Attempts:

3 left

💡 Hint

Common Mistakes

Using original keys without uppercase.

Filtering values less than or equal to zero.

Swapping keys and values in dictionary comprehension.

Keys are converted to uppercase with k.upper(), values are v, and filter keeps values greater than 0.