问使用numpy.loadtxt加载同时包含浮点数和字符串的文本文件

EN

5.1,3.5,1.4,0.2,Iris-setosa
4.9,3.0,1.4,0.2,Iris-setosa
5.8,2.7,4.1,1.0,Iris-versicolor
6.2,2.2,4.5,1.5,Iris-versicolor
6.4,3.1,5.5,1.8,Iris-virginica
6.0,3.0,4.8,1.8,Iris-virginica

np.loadtxt(open("data.txt"), 'r',
           dtype={
               'names': (
                   'sepal length', 'sepal width', 'petal length',
                   'petal width', 'label'),
               'formats': (
                   np.float, np.float, np.float, np.float, np.str)},
           delimiter= ',', skiprows=0)