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# -*- coding:utf-8 -*-
# author:
import numpy
'''ndarray数组重塑'''
x = numpy.arange(0,6) #[0 1 2 3 4]
print(x) #[0 1 2 3 4]
print(x.reshape((2,3))) #) [[0 1 2][3 4 5]]
print(x )#[0 1 2 3 4]
print(x.reshape((2,3)).reshape((3,2))) # [[0 1][2 3][4 5]]
y = numpy.array([[1,1,1],[1,1,1]])
x = x.reshape(y.shape)
print(x )# [[0 1 2][3 4 5]]
print(x.flatten() )# [0 1 2 3 4 5]
x.flatten()[0] = -1 # flatten返回的是拷贝
print(x )# [[0 1 2][3 4 5]]
print(x.ravel()) # [0 1 2 3 4 5]
x.ravel()[0] = -1 # ravel返回的是视图（引用） 
print(x) # [[-1 1 2][3 4 5]]
'''"维度大小自动推导"'''
arr = numpy.arange(15)
print(arr.reshape((5, -1))) # 15 / 5 = 3