python - 在Python中从字母数字数组中提取一行

Question

我在 python 中有这个数组，我想将以 p 结尾的行提取到一个新数组中。

array([[ 0,   6,   p],
       [ 1,   7,   m],
       [ 2,  10,   m],
       [ 3,   4,   p],
       [ 4,   1,   m],
       [ 5,  10,   p],
       [ 6,   6,   m],
       [ 7,   4,   m],
       [ 8,   6,   p],
       [ 9,   7,   p]])

Answer 1

简单的方法是使用 numpy bool 索引，如下所示

a = numpy.array(a) # ensure its a numpy array
print a[a[:,-1]=="p"]

分解它

mask = a[:,-1]=="p" #gives an array of True/False that is the same as the array, based on if last char is "p"
a[mask]  #indexes into the original array returning only the rows that end with "p"