Working with Arrays of Strings And Bytes

1. Remember

What is the default dtype for an array created with Unicode strings in NumPy?

|V5

Incorrect; it is used for numpy.void type, representing a collection of bytes.

|S5
np.unicode_

Incorrect; while intuitively it might seem right, NumPy uses the notation <U followed by a number to specify the length of Unicode strings.

<U5

2. Understand

Why would np.array([b"hello", b"world"]).astype(np.void) be preferred for byte streams?

Enhances the readability of bytestring data.
Represents data as a collection of 8-bit integers, useful for non-text byte streams.

Correct; using np.void is useful for representing byte streams as collections of 8-bit integers, especially when they don't represent text data.

It shortens the byte strings to improve memory efficiency.
It converts bytestrings into Unicode strings.

Incorrect; converting to np.void does not turn bytestrings into Unicode but treats them as raw byte collections.

3. Apply

How can you correctly convert the bytestring array np.array([b"hello", b"world"]) to represent it as an array of 8-bit integers?

import numpy as np\ndata = np.array([b"hello", b"world"])\nint_array = data.astype(np.void)\nprint(int_array)

Correct; using astype(np.void) converts the bytestring array into an array of byte collections, treating them as 8-bit integers, suitable for arbitrary binary data.

import numpy as np\ndata = np.array([b"hello", b"world"])\nint_array = np.array(data, dtype='|V5')\nprint(int_array)

Incorrect; though it seems like a plausible method to convert data types, the syntax is incorrect. The correct method to apply a dtype during array creation involves astype() for existing arrays, not np.array(data, dtype='|V5').

import numpy as np\ndata = np.array([b"hello", b"world"])\nint_array = data.astype('<U5'\nprint(int_array)

Incorrect; astype('<U5') attempts to convert the bytestrings into Unicode strings, not representing them as 8-bit integers.

import numpy as np\ndata = np.array([b"hello", b"world"])\nint_array = data.astype('|S5')\nprint(int_array)

Incorrect; astype('|S5') merely confirms the array as a bytestring of length 5, not converting it into an array of 8-bit integers.

1. Remember

2. Understand

3. Apply

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