Type promotion in operations in NumPy - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a NumPy array of integers.

NumPy

import numpy as np
arr = np.array([1, 2, 3], dtype="[1]")
print(arr.dtype)

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

Aint32

Bstr

Cfloat64

Dbool

Attempts:

3 left

💡 Hint

Common Mistakes

Using a float dtype when integers are needed.

Using string dtype which is not numeric.

The dtype int32 creates an integer array. This is important for type promotion in operations.

2fill in blank

medium

Complete the code to add an integer array and a float array, showing type promotion.

NumPy

import numpy as np
arr_int = np.array([1, 2, 3], dtype='int32')
arr_float = np.array([1.0, 2.0, 3.0], dtype="[1]")
result = arr_int + arr_float
print(result.dtype)

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Afloat32

Bint32

Cbool

Dstr

Attempts:

3 left

💡 Hint

Common Mistakes

Using int dtype for float array, which prevents promotion.

Using string dtype causing errors.

Adding int32 and float32 arrays promotes the result to float32 to avoid losing decimal information.

3fill in blank

hard

Fix the error in the code to correctly multiply an integer array by a float scalar with type promotion.

NumPy

import numpy as np
arr = np.array([1, 2, 3], dtype='int16')
scalar = [1]
result = arr * scalar
print(result.dtype)

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A'2'

B2

C2.0

DTrue

Attempts:

3 left

💡 Hint

Common Mistakes

Using integer scalar which does not promote type.

Using string scalar causing errors.

Using a float scalar (2.0) promotes the integer array to float in the multiplication result.

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', 'science', 'ai', 'ml']
lengths = {word: [1] for word in words if [2] > 3}
print(lengths)

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Alen(word)

Blen(words)

Cword

Dlen(word) > 3

Attempts:

3 left

💡 Hint

Common Mistakes

Using len(words) which is total list length.

Using word instead of length for filtering.

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

5fill in blank

hard

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

NumPy

words = ['cat', 'dog', 'a', 'bird']
[1] = {word.[2](): [3] for word in words if len(word) > 2}
print(result)

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Aresult

Bupper

Clen(word)

Dlower

Attempts:

3 left

💡 Hint

Common Mistakes

Using lower() instead of upper().

Not assigning the comprehension to a variable.

The dictionary comprehension maps each word in uppercase to its length, filtering words longer than 2 characters.