np.zeros() for zero-filled arrays in NumPy - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a zero-filled array of length 5.

NumPy

import numpy as np
arr = np.[1](5)
print(arr)

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

Azeros

Bones

Cempty

Dfull

Attempts:

3 left

💡 Hint

Common Mistakes

Using np.ones() which creates an array filled with ones.

Using np.empty() which creates an uninitialized array with random values.

The np.zeros() function creates an array filled with zeros. Here, it creates an array of length 5 filled with zeros.

2fill in blank

medium

Complete the code to create a 2x3 zero-filled array.

NumPy

import numpy as np
arr = np.zeros([1])
print(arr)

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

A(2, 3)

B[3, 2]

C(3, 2)

D[2, 3]

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the dimensions, creating 3 rows and 2 columns instead.

Using a tuple with wrong order.

The shape argument for np.zeros() is a tuple or list indicating the dimensions. Here, [2, 3] creates 2 rows and 3 columns.

3fill in blank

hard

Fix the error in the code to create a zero-filled array of shape (4, 4).

NumPy

import numpy as np
arr = np.zeros([1])
print(arr)

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

A[4, 4]

B(4, 4)

C{4, 4}

D4, 4

Attempts:

3 left

💡 Hint

Common Mistakes

Passing two separate arguments instead of one tuple.

Using square or curly brackets which are invalid here.

The shape argument must be a single tuple. So np.zeros((4, 4)) is correct. Using separate arguments or other brackets causes errors.

4fill in blank

hard

Fill both blanks to create a zero-filled array of integers with shape (3, 2).

NumPy

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

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

A(3, 2)

Bint

Cfloat

D[3, 2]

Attempts:

3 left

💡 Hint

Common Mistakes

Using a list instead of a tuple for shape.

Using float instead of int for dtype.

The shape must be a tuple like (3, 2). The dtype argument sets the data type; int makes the array hold integers.

5fill in blank

hard

Fill all three blanks to create a zero-filled 3D array with shape (2, 3, 4) and float data type.

NumPy

import numpy as np
arr = np.zeros([1], dtype=[2], order=[3])
print(arr.shape, arr.dtype)

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

A(2, 3, 4)

Bfloat

C'C'

D'F'

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong shape dimensions or wrong brackets.

Using int instead of float for dtype.

Using 'F' order without understanding memory layout.

The shape is a tuple with three dimensions: (2, 3, 4). The dtype is float for floating-point zeros. The order 'C' means row-major order, which is common.

Practice

1. What does the np.zeros() function do in NumPy?

easy

A. Creates an array filled with zeros

B. Creates an array filled with ones

C. Creates an array with random values

D. Creates an empty array with no elements

Solution

1. Step 1: Understand the purpose of np.zeros()

   This function is designed to create arrays where every element is zero.

2. Step 2: Compare with other array creation functions

   Unlike np.ones() or random array functions, np.zeros() specifically fills the array with zeros.

3. Final Answer:

   Creates an array filled with zeros -> Option A

4. Quick Check:

   np.zeros() = zero-filled array [OK]

Hint: Remember zeros means all elements are zero [OK]

Common Mistakes:

• Confusing with np.ones()
• Thinking it creates empty arrays
• Assuming it creates random values

2. Which of the following is the correct syntax to create a 3x3 zero-filled array using NumPy?

easy

A. np.zeros(3,3)

B. np.zeros[3,3]

C. np.zeros((3,3))

D. np.zeros{3,3}

Solution

1. Step 1: Check the shape argument format

   The shape must be passed as a tuple, so it should be (3,3).

2. Step 2: Validate the function call syntax

   Only parentheses () are valid for function calls, so np.zeros((3,3)) is correct.

3. Final Answer:

   np.zeros((3,3)) -> Option C

4. Quick Check:

   Shape as tuple inside parentheses [OK]

Hint: Use double parentheses for shape tuple [OK]

Common Mistakes:

• Using commas without tuple
• Using square or curly brackets
• Missing parentheses

3. What is the output of the following code?

import numpy as np
arr = np.zeros(4, dtype=int)
print(arr)

medium

A. [0 0 0 0]

B. [0. 0. 0. 0.]

C. [1 1 1 1]

D. [False False False False]

Solution

1. Step 1: Understand np.zeros(4, dtype=int)

   This creates a 1D array of length 4 filled with zeros, with integer type.

2. Step 2: Check the printed output format

   Since dtype is int, zeros are printed as integers without decimal points.

3. Final Answer:

   [0 0 0 0] -> Option A

4. Quick Check:

   Integer zeros printed without decimals [OK]

Hint: dtype=int means zeros print as integers [OK]

Common Mistakes:

• Expecting float zeros with decimals
• Confusing with ones array
• Thinking output is boolean

4. Identify the error in this code snippet:

import numpy as np
arr = np.zeros[5]
print(arr)

medium

A. Missing dtype argument

B. Using square brackets instead of parentheses for function call

C. Shape argument should be a tuple

D. np.zeros cannot create 1D arrays

Solution

1. Step 1: Check function call syntax

   Functions in Python require parentheses (), not square brackets [].

2. Step 2: Confirm correct usage of np.zeros

   The shape argument can be an integer for 1D arrays, so 5 is valid.

3. Final Answer:

   Using square brackets instead of parentheses for function call -> Option B

4. Quick Check:

   Function calls need parentheses [OK]

Hint: Use () for functions, not [] [OK]

Common Mistakes:

• Using [] instead of ()
• Thinking dtype is mandatory
• Confusing shape tuple for 1D arrays

5. You want to create a zero-filled 2D array with 3 rows and 4 columns, but the array must store boolean values. Which code is correct?

hard

A. np.zeros((3,4), type=bool)

B. np.zeros(3,4, dtype=bool)

C. np.zeros([3,4], dtype=bool)

D. np.zeros((3,4), dtype=bool)

Solution

1. Step 1: Check shape argument format

   The shape must be a tuple, so (3,4) is correct.

2. Step 2: Verify dtype argument name and value

   The correct keyword is dtype, and bool is valid to create boolean arrays.

3. Step 3: Eliminate incorrect options

   Using the wrong keyword type instead of dtype, passing shape as separate arguments like np.zeros(3,4, dtype=bool) without tuple parentheses, using a list [3,4] instead of tuple.

4. Final Answer:

   np.zeros((3,4), dtype=bool) -> Option D

5. Quick Check:

   Shape tuple and dtype=bool required [OK]

Hint: Use tuple for shape and dtype=bool for boolean zeros [OK]

Common Mistakes:

• Passing shape as separate args
• Using list instead of tuple
• Wrong keyword 'type' instead of 'dtype'