Python逻辑运算报错The truth value of an array with more than one element is ambiguous.Use a.any() or a.all

在python逻辑运算时

a[0

或a[0

都会报错:ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

报错的原始是，[]的运算改变了数组维度，正确的适用方法是：

a[(a>0) & (a<1)] # 一定要有括号
或  a[np.logical_and(a>0, a<1)]

Refs:

https://stackoverflow.com/questions/12647471/the-truth-value-of-an-array-with-more-than-one-element-is-ambigous-when-trying-t

https://stackoverflow.com/questions/34472814/use-a-any-or-a-all