为什么查询列信息写成1:23也不会报错？

In [85]: arraytest5[0:5,1:4]
Out[85]:
array([[10],
       [20],
       [30],
       [40],
       [50]])

In [86]: arraytest5
Out[86]:
array([[ 4, 10],
       [12, 20],
       [20, 30],
       [28, 40],
       [36, 50]])

In [87]: arraytest5[0:5,1:1]
Out[87]: array([], shape=(5, 0), dtype=int64)

In [88]: arraytest5[0:5,1:10]
Out[88]:
array([[10],
       [20],
       [30],
       [40],
       [50]])

In [89]: arraytest5[0:5,0:10]
Out[89]:
array([[ 4, 10],
       [12, 20],
       [20, 30],
       [28, 40],
       [36, 50]])

In [90]: arraytest5[0:5,0:1]
Out[90]:
array([[ 4],
       [12],
       [20],
       [28],
       [36]])

In [91]: arraytest5[0:5,0:0]
Out[91]: array([], shape=(5, 0), dtype=int64)

In [92]: arraytest5[0:5,0:1]
Out[92]:
array([[ 4],
       [12],
       [20],
       [28],
       [36]])

In [93]: arraytest5[0:5,1:0]
Out[93]: array([], shape=(5, 0), dtype=int64)

In [94]: arraytest5[0:5,1:1
    ...: ]
Out[94]: array([], shape=(5, 0), dtype=int64)

In [95]: arraytest5[0:5,1:]
Out[95]:
array([[10],
       [20],
       [30],
       [40],
       [50]])

In [96]: arraytest5[0:5,1:2]
Out[96]:
array([[10],
       [20],
       [30],
       [40],
       [50]])

In [97]: arraytest5[0:5,1:23
    ...: ]
Out[97]:
array([[10],
       [20],
       [30],
       [40],
       [50]])

[此贴子已经被作者于2019-11-13 17:27编辑过]