Numpy: Insert items in an array

# Import library
import numpy as np

# Create 1-D array
x = np.array([1,2,3]) 

# Append
y = np.insert(arr=x, obj=0, values=999) # Default axis=None

# Output
print('Original array:\n', x, '\n', 'Shape:',x.shape,'\n')
print('After insert:\n', y, '\n', 'Shape:',y.shape,'\n')

Original array:
 [1 2 3] 
 Shape: (3,) 

After insert:
 [999   1   2   3] 
 Shape: (4,) 

# Import library
import numpy as np

# Create 2-D array
x = np.array([[1,2],
             [3,4]]) 

# Append
y = np.insert(arr=x, obj=0, values=[888,999], axis=0) 

# Output
print('Original array:\n', x, '\n', 'Shape:',x.shape,'\n')
print('After insert:\n', y, '\n', 'Shape:',y.shape,'\n')

Original array:
 [[1 2]
 [3 4]] 
 Shape: (2, 2) 

After insert:
 [[888 999]
 [  1   2]
 [  3   4]] 
 Shape: (3, 2)

# Import library
import numpy as np

# Create 2-D array
x = np.array([[1,2],
             [3,4]]) 

# Append
y = np.insert(arr=x, obj=0, values=999, axis=1) 

# Output
print('Original array:\n', x, '\n', 'Shape:',x.shape,'\n')
print('After insert:\n', y, '\n', 'Shape:',y.shape,'\n')

Original array:
 [[1 2]
 [3 4]] 
 Shape: (2, 2) 

After insert:
 [[999   1   2]
 [999   3   4]] 
 Shape: (2, 3)