Question

Using the arrays created in Question 4 above, write NumPy commands for the following:

1. Find the dimensions, shape, size, data type of the items and itemsize of arrays zeros, vowels, ones, myarray1 and myarray2.
2. Reshape the array ones to have all the 10 elements in a single row.
3. Display the 2^nd and 3^rd element of the array vowels.
4. Display all elements in the 2^nd and 3^rd row of the array myarray1.
5. Display the elements in the 1^st and 2^nd column of the array myarray1.
6. Display the elements in the 1st column of the 2^nd and 3^rd row of the array myarray1.
7. Reverse the array of vowels.

Answer 1

a) 

print("zeros:")
print("Dimensions:", zeros.ndim)
print("Shape:", zeros.shape)
print("Size:", zeros.size)
print("Data type:", zeros.dtype)
print("Itemsize:", zeros.itemsize)

print("\nvowels:")
print("Dimensions:", vowels.ndim)
print("Shape:", vowels.shape)
print("Size:", vowels.size)
print("Data type:", vowels.dtype)
print("Itemsize:", vowels.itemsize)

print("\nones:")
print("Dimensions:", ones.ndim)
print("Shape:", ones.shape)
print("Size:", ones.size)
print("Data type:", ones.dtype)
print("Itemsize:", ones.itemsize)

print("\nmyarray1:")
print("Dimensions:", myarray1.ndim)
print("Shape:", myarray1.shape)
print("Size:", myarray1.size)
print("Data type:", myarray1.dtype)
print("Itemsize:", myarray1.itemsize)

print("\nmyarray2:")
print("Dimensions:", myarray2.ndim)
print("Shape:", myarray2.shape)
print("Size:", myarray2.size)
print("Data type:", myarray2.dtype)
print("Itemsize:", myarray2.itemsize)

Output:

zeros:
Dimensions: 2
Shape: (2, 3)
Size: 6
Data type: float64
Itemsize: 8

vowels:
Dimensions: 1
Shape: (5,)
Size: 5
Data type: <U1
Itemsize: 4

ones:
Dimensions: 1
Shape: (10,)
Size: 10
Data type: float64
Itemsize: 8

myarray1:
Dimensions: 2
Shape: (3, 3)
Size: 9
Data type: int64
Itemsize: 8

myarray2:
Dimensions: 2
Shape: (2, 2)
Size: 4
Data type: int64
Itemsize: 8

b) 

ones = ones.reshape(1, 10)
print(ones)

Output:

[[1. 1. 1. 1. 1. 1. 1. 1. 1. 1.]]

c) 

print("\n2nd and 3rd elements of vowels:")
print(vowels[1:3])

Output:

2nd and 3rd elements of vowels:
['e' 'i']

d) 

print("\n2nd and 3rd rows of myarray1:")
print(myarray1[1:3])

Output:

2nd and 3rd rows of myarray1:

[[4	5	5]
[7	8	9]]

e) 

print("\n1st and 2nd columns of myarray1:")
print(myarray1[:, 0:2])

Output:

1st and 2nd columns of myarray1:

[1	2]
[4	5]
[7	8]]

f) 

print("\n1st column of 2nd and 3rd rows:")
print(myarray1[1:3, 0])

Output:

1st column of 2nd and 3rd rows:
[4 7]

g) 

print("\nReverse of vowels:")
print(vowels[::-1])

Output:

Reverse of vowels:
['u' 'o' 'i' 'e' 'a']