python – 使用numpy.genfromtxt给出TypeError：无法隐式地将’b

以下是前3行数据集(目标列是第19列,功能是前18列)：

user    gender  age how_tall_in_meters  weight  body_mass_index x1  
debora  Woman   46  1.62    75  28.6    -3  
debora  Woman   46  1.62    75  28.6    -3

此处未显示的目标列具有字符串值.

from pandas import read_csv
import numpy as np
from sklearn.linear_model.stochastic_gradient import SGDClassifier
from sklearn import preprocessing
import sklearn.metrics as metrics
from sklearn.cross_validation import train_test_split

#d = pd.read_csv("data.csv",dtype={'A': np.str(),'B': np.str(),'S': np.str()})

dataset = np.genfromtxt(open('data.csv','r'),delimiter=',',dtype='f8')[1:]
target = np.array([x[19] for x in dataset])
train = np.array([x[1:] for x in dataset])

print(target)

我得到的错误是：

Traceback (most recent call last):
  File "C:UsersCameronDesktopProject - Machine learningdatafilesforprojSGD_classifier.py",line 12,in <module>
    dataset = np.genfromtxt(open('data.csv',dtype='f8')[1:]
  File "C:Python33libsite-packagesnumpylibnpyio.py",line 1380,in genfromtxt
    first_values = split_line(first_line)
  File "C:Python33libsite-packagesnumpylib_iotools.py",line 217,in _delimited_splitter
    line = line.split(self.comments)[0]
TypeError: Can't convert 'bytes' object to str implicitly