python - 修剪/去除 numpy 数组的零点

Question

如何删除 numpy 数组的前导/尾随零？

import numpy as np
a = np.array([0,0,0,3,2,-1,0,0,7,9,13,0,0,0,0,0,0,0])

#Desired output
[3,2,-1,0,0,7,9,13]

这行不通:

a[a != 0]    

因为它会删除所有的零，包括内部的零。

Answer 1

使用numpy.trim_zeros :

>>> import numpy as np
>>> a = np.array([0,0,0,3,2,-1,0,0,7,9,13,0,0,0,0,0,0,0])
>>> np.trim_zeros(a)
array([ 3,  2, -1,  0,  0,  7,  9, 13])