Numpy Tutorial_3

 

Numpy Array Indexing

#Working with 1-Dimension array

import numpy as np

L = [1,2,3,4,5]

N = np.array(L)

print(N.ndim)

print(N.shape)

print(N[0]+N[4]) # 1 + 4 

print(N[0])

print(N[1])

print(N[-1])

print(N>3)

print(N[N>3])# convert bool to value

odd = N[N%2==1]  # print the odd value 

print(odd)

1
(5,)
6
1
2
5
[False False False  True  True]
[4 5]
[1 3 5]

#Working with 2-Dimension array

import numpy as np

L = [[1,2,3,4,5]]

N = np.array(L)

print(N.ndim)

print(N.shape)

print(N[0,0]+N[0,1]) # 1 + 4 

print(N[0,0])# 0 represent row, 0 represent column, so in row we can not wrote more than 0 coz it just one row 

print(N[0,4])# in column we can not wrote more than 4 coze it just 5 column

2
(1, 5)
3
1
5

#Working with 3-Dimension array

import numpy as np

L = [[[1,2,3,4,5]]]

N = np.array(L)

print(N.ndim)

print(N.shape)

print(N[0,0,0]+N[0,0,1]) # 1 + 4 

print(N[0,0,0])# 0 represent row, 0 represent column, so in row we can not wrote more than 0 coz it just one row 

print(N[0,0,4])# in column we can not wrote more than 4 coze it just 5 column

​

​

3
(1, 1, 5)
3
1
5

L1 = [1,2,3,4]

L2 = [6,7,8,9]

arr = np.array([L1,L2])

print(arr)

print(arr[1,2])

print(arr.ndim)

print(arr.shape)# 2,4 two row, 4 column

[[1 2 3 4]
 [6 7 8 9]]
8
2
(2, 4)

N = np.array([[[1,2,3]]])

print(N[0,0,1])

2

N = np.array([[[1,2,3],[4,5,6]]])

print(N)

print(N[0,1,2])

print(N[0,1,-1]) #print the last element of array

[[[1 2 3]
  [4 5 6]]]
6
6

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