如何修复: ValueError: labels=21638的数量与samples=13的数量不匹配

Question

我对python 2.7非常陌生，我试图在我的数据集上运行决策树分类器，但是在一个教程之后，我首先将我的特性列向量化并保存到一个数组中，然后使用标签编码器将目标列保存在数组中。请你解释一下我该如何纠正这个错误。

数据：

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代码：

import pandas as pd

dataset = "C:/Users/ashik swaroop/Desktop/anaconda/Gene Dataset/Final.csv"
datacan = pd.read_csv(dataset)
datacan = datacan.fillna('')
features = datacan[[ 
"Tumour_Types_Somatic","Tumour_Types_Germline",
"Cancer_Syndrome","Tissue_Type", 
"Role_in_Cancer","Mutation_Types","Translocation_Partner",
"Other_Syndrome","Tier","Somatic","Germline",
"Molecular_Genetics","Other_Germline_Mut"]]

 from sklearn.feature_extraction import DictVectorizer
from sklearn.preprocessing import LabelEncoder

X_dict = features.to_dict().values()
vect = DictVectorizer(sparse=False)
X_vector = vect.fit_transform(X_dict)

le = LabelEncoder()
y_train = le.fit_transform(datacan['Gene_Symbol'][:-1])


X_Train = X_vector[:-1]

X_Test = X_vector[-1:] 

from sklearn import tree

clf = tree.DecisionTreeClassifier(criterion='entropy')
clf = clf.fit(X_Train,y_train)    `

我得到了这个错误：

from sklearn import tree
clf = tree.DecisionTreeClassifier(criterion='entropy')
clf = clf.fit(X_Train,y_train)
Traceback (most recent call last):

File "<ipython-input-49-fef4fc045a54>", line 4, in <module>
clf = clf.fit(X_Train,y_train)

File "C:\Users\ashik swaroop\Anaconda2\lib\site- 
packages\sklearn\tree\tree.py", line 739, in fit
X_idx_sorted=X_idx_sorted)

File "C:\Users\ashik swaroop\Anaconda2\lib\site- 
packages\sklearn\tree\tree.py", line 240, in fit
"number of samples=%d" % (len(y), n_samples))

ValueError: Number of labels=21638 does not match number of samples=12

Traceback (most recent call last):

File "<ipython-input-49-fef4fc045a54>", line 4, in <module>
clf = clf.fit(X_Train,y_train)

File "C:\Users\ashik swaroop\Anaconda2\lib\site- 
packages\sklearn\tree\tree.py", line 739, in fit
X_idx_sorted=X_idx_sorted)

File "C:\Users\ashik swaroop\Anaconda2\lib\site- 
packages\sklearn\tree\tree.py", line 240, in fit
"number of samples=%d" % (len(y), n_samples))

ValueError: Number of labels=21638 does not match number of samples=12

Answer 1

首先，要理解错误:似乎你的训练样本数(即。np.shape(X_train)[0])不匹配标签的数量(即。np.shape(y_train)[0])。

在查看您的代码时，我注意到了一些不一致的地方。请参阅下面的内联评论。

import pandas as pd
from apyori import apriori
dataset = "C:/Users/ashik swaroop/Desktop/anaconda/Gene Dataset/Final.csv"
datacan = pd.read_csv(dataset)
datacan = datacan.fillna('')
features = datacan[[ 
"Tumour_Types_Somatic","Tumour_Types_Germline",
"Cancer_Syndrome","Tissue_Type", 
"Role_in_Cancer","Mutation_Types","Translocation_Partner",
"Other_Syndrome","Tier","Somatic","Germline",
"Molecular_Genetics","Other_Germline_Mut"]]
# EDIT replace by features = [ 
#"Tumour_Types_Somatic","Tumour_Types_Germline",
#"Cancer_Syndrome","Tissue_Type", 
#"Role_in_Cancer","Mutation_Types","Translocation_Partner",
#"Other_Syndrome","Tier","Somatic","Germline",
#"Molecular_Genetics","Other_Germline_Mut"]

orders = datacan[features].to_dict( orient = 'records' ) # this variable is not used

from sklearn.feature_extraction import DictVectorizer
from sklearn.preprocessing import LabelEncoder

X_dict = features.to_dict().values() # try replacing this line with X_dict = orders
vect = DictVectorizer(sparse=False)
X_vector = vect.fit_transform(X_dict)

le = LabelEncoder()
y_train = le.fit_transform(datacan['Gene_Symbol'][:-1])


X_Train = X_vector[:-1]

X_Test = X_vector[-1:] 

from sklearn import tree

clf = tree.DecisionTreeClassifier(criterion='entropy')
clf = clf.fit(X_Train,y_train)