将预测结果合并到原始数据框？

Question

我已经完成了一个机器学习算法，可以从文本中分类类别。我已经完成了 99%，但是我现在知道将我的预测结果合并回原始数据帧，以查看我开始的内容和预测内容的打印视图。

下面是我的代码。

#imports data from excel file and shows first 5 rows of data
file_name = r'C:\Users\aac1928\Documents\Machine Learning\Training        Data\RFP Training Data.xlsx'
sheet = 'Sheet1'

import pandas as pd
import numpy
import xlsxwriter
import sklearn

df = pd.read_excel(io=file_name,sheet_name=sheet)

#extracts specifics rows from data 
data = df.iloc[: , [0,2]]
print(data)

#Gets data ready for model
newdata = df.iloc[:,[1,2]]
newdata = newdata.rename(columns={'Label':'label'})
newdata = newdata.rename(columns={'RFP Question':'question'})
print(newdata)

# how to define X and yfor use with COUNTVECTORIZER
X = newdata.question
y = newdata.label
print(X.shape)
print(y.shape)

# split X and y into training and testing sets
X_train = X
y_train = y
X_test = newdata.question[:50]
y_test = newdata.label[:50]
print(X_train.shape)
print(X_test.shape)
print(y_train.shape)
print(y_test.shape)

# import and instantiate CountVectorizer (with the default parameters)
from sklearn.feature_extraction.text import CountVectorizer
vect = CountVectorizer()

# equivalently: combine fit and transform into a single step
X_train_dtm = vect.fit_transform(X_train)

# transform testing data (using fitted vocabulary) into a document-term matrix
X_test_dtm = vect.transform(X_test)
X_test_dtm

# import and instantiate a logistic regression model
from sklearn.linear_model import LogisticRegression
logreg = LogisticRegression()

# train the model using X_train_dtm
%time logreg.fit(X_train_dtm, y_train)

# make class predictions for X_test_dtm
y_pred_class = logreg.predict(X_test_dtm)
y_pred_class

# calculate predicted probabilities for X_test_dtm (well calibrated)
y_pred_prob = logreg.predict_proba(X_test_dtm)[:, 1]
y_pred_prob

# calculate accuracy
metrics.accuracy_score(y_test, y_pred_class)

这是我添加的新数据，用于与数组长度相同的预测

# split X and y into training and testing sets
X_train = X
y_train = y
X_testnew = dfpred.question
y_testnew = dfpred.label
print(X_train.shape)
print(X_testnew.shape)
print(y_train.shape)
print(y_testnew.shape)

(447,) (168,) (447,) (168,)

# transform new testing data (using fitted vocabulary) into a document-term matrix
X_test_dtm_new = vect.transform(X_testnew)
X_test_dtm_new

# make class predictions for new X_test_dtm
y_pred_class_new = nb.predict(X_test_dtm_new)
y_pred_class_new

数组([ 3, 3, 19, 18, 5, 10, 10, 5, 19, 3, 3, 3, 5, 3, 3, 3, 3, 9, 19, 5, 5, 10, 9, 5, 18, 19, 9, 9, 19, 19, 18, 18, 18, 4, 18, 3, 9, 18, 19, 19, 18, 19, 5, 19, 19, 3, 3, 18, 18, 5, 18, 3, 4, 5, 6, 4, 5, 19, 19, 5, 5, 19, 19, 4, 5, 18, 5, 5, 19, 5, 18, 5, 19, 18, 19, 5, 7, 5, 9, 9, 9, 9, 10, 9, 9, 5, 5, 5, 5, 3, 18, 4, 9, 5, 3, 6, 9, 18, 7, 5, 9, 5, 5, 19, 5, 5, 19, 5, 6, 5, 5, 6, 9, 21, 10, 9, 18, 9, 9, 3, 18, 5, 6, 18, 6, 3, 6, 5, 18, 6, 5, 18, 5, 6, 7, 7, 5, 7, 19, 18, 6, 5, 5, 5, 5, 5, 19, 16, 5, 19, 5, 5, 5, 5、19、5、7、19、6、7、3、18、18、18、6、19、19、7]、 dtype=int64)

# calculate predicted probabilities for X_test_dtm (well calibrated)
y_pred_prob_new = logreg.predict_proba(X_test_dtm_new)[:, 1]
y_pred_prob_new

df['prediction'] = pd.Series(y_pred_class_new)

dfout = pd.merge(dfpred,df['prediction'].dropna() .to_frame(),how = 'left',left_index = True,   right_index = True)

打印（dfout）

我希望这有助于我尽可能清楚

Answer 1

我认为由于您的预测只是一个数组，因此最好使用：

df['predictions'] = y_pred_class

Answer 2

我认为您的问题是您的预测数组比原来的 df 短，因为您分为训练集和测试集。

您定义为 newdata.question[:50] 的 X_test 数组看起来好像您正在获取该列的最后 50 行。

我要做的是创建一个与您的预测数组长度相同的 prediction_df。在您的情况下，您需要的行是原始 df 的最后 50 行。

prediction_df = df.iloc[:50]
prediction_df['predictions'] = y_pred_class

只需确保您的 prediction_df 行与您用来制作 X_test 的行匹配！