Merge Predictions with whole data set

[mayanksrivastava]

A very basic question. We have dataset with experience and salary

now i wanted to merge my predictions and create an output with experience and the predicted salary, How do I do this in python.

below is my code. what should i change here ?

#Importing Libraries 
import pandas as pd 
import numpy as np 
import matplotlib.pyplot as mp

#Import Dataset 
data = pd.read_csv('H:\Data\Simple_Linear_Regression\Salary_Data.csv')
x = data.iloc[:, :-1].values
y = data.iloc[:, 1:2]

#Split into train and test 
from sklearn.cross_validation import train_test_split 
xtrain, xtest, ytrain, ytest = train_test_split(x,y, test_size = 1/3, random_state = 0)

#Fit Linear Regression Model 
from sklearn.linear_model import LinearRegression 
regressor = LinearRegression()
regressor.fit(xtrain,ytrain)
regressor.score(xtrain,ytrain)

#Predict Salary 
ypred = regressor.predict(xtest)

DataSet:

YearsExperience Salary
1.1 39343.0
1.3 46205.0
1.5 37731.0
2.0 43525.0
2.2 39891.0
2.9 56642.0
3.0 60150.0
3.2 54445.0
3.2 64445.0