使用knn分类时出现ValueError: could not convert string to float错误

Question

问题遇到的现象和发生背景

使用knn分类器进行训练时发生错误

问题相关代码，请勿粘贴截图

# coding=utf-8

import pandas as pd

# 创建特征列表
from sklearn import preprocessing


column_names = ["P_rect", "P_extend", "P_spherical", "P_leaf", "P_circle", "Species"]
#column_names = ['P_rect', 'P_extend', 'P_spherical', 'P_leaf', 'P_circle','P_complecate', 'Species']
data = pd.read_csv('data/data.csv', names=column_names)



#print (data.shape)

# 这个功能快要被抛弃了,分割训练和测试集
from sklearn.model_selection import KFold
from sklearn.model_selection import train_test_split


X_train, X_test, Y_train, Y_test = train_test_split(data[column_names[0:5]], data[column_names[5]], test_size=0.25, random_state=33)

#print (Y_train.value_counts())
#print (Y_test.value_counts())

# 数据整理，但是整形的，需要注意
#from sklearn.preprocessing import StandardScaler
#ss = StandardScaler()
#X_train = ss.fit_transform(X_train)
#X_test = ss.transform(X_test)


from sklearn.neighbors import KNeighborsClassifier

knc = KNeighborsClassifier()
knc.fit(X_train, Y_train)
knc_y_predict = knc.predict(X_test)

from sklearn.metrics import classification_report

print ("LR 精确度：" + str(knc.score(X_test, Y_test)))
print (classification_report(Y_test, knc_y_predict, target_names=['fly','wo','jingui','zhang','zhizhu']))

# 保存训练结果，供后面直接使用
import joblib

joblib.dump(knc,'model/knc.model')

运行结果及报错内容

Traceback (most recent call last):
  File "C:\Users\Administrator\PycharmProjects\Insect_Identification\KneiborsClassfier.py", line 37, in <module>
    knc.fit(X_train, Y_train)
  File "D:\Anaconda3\lib\site-packages\sklearn\neighbors\_classification.py", line 179, in fit
    return self._fit(X, y)
  File "D:\Anaconda3\lib\site-packages\sklearn\neighbors\_base.py", line 363, in _fit
    X, y = self._validate_data(X, y, accept_sparse="csr",
  File "D:\Anaconda3\lib\site-packages\sklearn\base.py", line 433, in _validate_data
    X, y = check_X_y(X, y, **check_params)
  File "D:\Anaconda3\lib\site-packages\sklearn\utils\validation.py", line 63, in inner_f
    return f(*args, **kwargs)
  File "D:\Anaconda3\lib\site-packages\sklearn\utils\validation.py", line 871, in check_X_y
    X = check_array(X, accept_sparse=accept_sparse,
  File "D:\Anaconda3\lib\site-packages\sklearn\utils\validation.py", line 63, in inner_f
    return f(*args, **kwargs)
  File "D:\Anaconda3\lib\site-packages\sklearn\utils\validation.py", line 673, in check_array
    array = np.asarray(array, order=order, dtype=dtype)
  File "D:\Anaconda3\lib\site-packages\numpy\core\_asarray.py", line 102, in asarray
    return array(a, dtype, copy=False, order=order)
  File "D:\Anaconda3\lib\site-packages\pandas\core\generic.py", line 1993, in __array__
    return np.asarray(self._values, dtype=dtype)
  File "D:\Anaconda3\lib\site-packages\numpy\core\_asarray.py", line 102, in asarray
    return array(a, dtype, copy=False, order=order)
ValueError: could not convert string to float: 'True'

我的解答思路和尝试过的方法

尝试使用LabelEncoder ：将字符串转换为增量值但是好像没成功

我想要达到的结果

Answer 1

这个函数返回含有label，也就是字符串，你先print出来看看是写啥label，然后把他去除掉。