Copy() in Python numpy (copy)

Not replicated （No Copy at All）

Specific explanation ：

import numpy as np
a = np.arange(12) #a For a sequence
b = a # No new objects have been created
print('a Of shape by ：', a.shape) # Output a The size of the
print('b yes a Do you ？', b is a) #ab Two names for the same object
b.shape = 3, 4 # take b Of shape change
print('a Of shape Turn into ：', a.shape) #a Of shanpe And it changed

Output results ：

a Of shape by ： (12,)
b yes a Do you ？ True
a Of shape Turn into ： (3, 4)

View or shallow copy （View or Shallow Copy）

Different array objects can type the same data ,view Method to create a new object that is the same as the original array .

Specific explanation

a = np.arange(12)
c = a.view() # Build a and a Same c
print('c When not changed a Of shape by ：', a.shape) # Output a The size of the
print('c yes a Do you ？', c is a)
print('c In order to a Based on it ', c.base is a)
c.shape = 3, 4
print('c After change a Of shape by ：', a.shape)

Output results ：

c When not changed a Of shape by ： (12,)
c yes a Do you ？ False
c In order to a Based on it True
c After change a Of shape by ： (12,)

Deep copy （Deep Copy）

This is the time d yes a Copy , Just a simple copy , There's nothing to do with the two ：

Specific explanation

a = np.arange(12)
d = a.copy() # Build a and a Same c
print('d yes a Do you ？', d is a)
print('d In order to a Based on it ', d.base is a)

Output results ：

d yes a Do you ？ False
d In order to a Based on it False