Python 根据指定的值从.dat文件中选择元素

我有一个.dat文件，格式如下：

   1.5699000000000001       -10.230000000000000                3
   1.5978000000000001       -10.550000000000001                3
   1.2388999999999999       -9.7100000000000009                3
   1.9540999999999999       -12.910000000000000                4
   1.7915000000000001       -12.539999999999999                4
   1.7547999999999999       -10.740000000000000                4
   1.8927000000000000       -10.800000000000001                4
   1.9222999999999999       -10.869999999999999                4
   1.9047000000000001       -11.770000000000000                4
   1.8488000000000000       -12.279999999999999                4
   1.6536000000000000       -10.690000000000000                3
   1.7059000000000000       -11.410000000000000                4
   1.7834000000000001       -12.250000000000000                4
   1.4136000000000000       -9.7699999999999996                3
   1.8093999999999999       -10.990000000000000                4
   1.4621999999999999       -10.490000000000000                4
   1.4086000000000001       -10.670000000000000                3
   1.5290999999999999       -10.660000000000000                3
   1.5990000000000000       -10.619999999999999                3
   1.9164000000000001       -12.580000000000000                4
   1.9463999999999999       -12.580000000000000                4
   1.6439999999999999       -12.340000000000000                4
   1.8986000000000001       -12.270000000000000                4
   1.4316000000000000       -10.029999999999999                4
   1.8346000000000000       -11.000000000000000                4
   1.3900999999999999       -10.650000000000000                3

首先，我想知道如何将其设置为numpy数组，也许可以使用numpy模块中的

fromfile

其次，我如何将其进一步分为两个数组，一个用于包含“3”的元素，另一个用于包含“4”…？

Plz使用：

Plz用途：

---

如问题所示，它是一种间隔格式，文件是.dat，-1是从哪里来的？不管怎样，让我知道它是否有效。效果非常好，可能是因为口语中使用了“Plz”而被标记了？它是一种间隔格式，如问题所示，文件是.dat，-1来自哪里？不管怎样，让我知道它是否有效。效果非常好，也许有人因为口语中使用了“Plz”而被减价了？

In [8]:

import numpy as np

A = np.genfromtxt('your_file.dat')

In [9]:

print A[A[:,2]==3]

[[  1.5699 -10.23     3.    ]
 [  1.5978 -10.55     3.    ]
 [  1.2389  -9.71     3.    ]
 [  1.6536 -10.69     3.    ]
 [  1.4136  -9.77     3.    ]
 [  1.4086 -10.67     3.    ]
 [  1.5291 -10.66     3.    ]
 [  1.599  -10.62     3.    ]
 [  1.3901 -10.65     3.    ]]

In [10]:

print A[A[:,2]==4]

[[  1.9541 -12.91     4.    ]
 [  1.7915 -12.54     4.    ]
 [  1.7548 -10.74     4.    ]
 [  1.8927 -10.8      4.    ]
 [  1.9223 -10.87     4.    ]
 [  1.9047 -11.77     4.    ]
 [  1.8488 -12.28     4.    ]
 [  1.7059 -11.41     4.    ]
 [  1.7834 -12.25     4.    ]
 [  1.8094 -10.99     4.    ]
 [  1.4622 -10.49     4.    ]
 [  1.9164 -12.58     4.    ]
 [  1.9464 -12.58     4.    ]
 [  1.644  -12.34     4.    ]
 [  1.8986 -12.27     4.    ]
 [  1.4316 -10.03     4.    ]
 [  1.8346 -11.       4.    ]]