CH1: KeyError: "['GDP per capita'] not in index"

I have tried all my level best to run the code from CH1. Copied as it as but getting different errors every time. Fixed many erros and but stuck at this errors. Can one of you help please..
KeyError: "['GDP per capita'] not in index"

Code below
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```python
import matplotlib
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
import sklearn.linear_model

#load the data
oecd_bli = pd.read_csv("OECD_BLI_2017.csv",thousands=',')
gdp_per_capita = pd.read_csv("gdp_per_capita.csv",thousands=',',delimiter=','
,encoding='latin1',na_values='n/a')

#prepare the data
def prepare_country_stats(oecd_bli, gdp_per_capita):
#get the pandas dataframe of GDP per capita and Life satisfaction
oecd_bli = oecd_bli[oecd_bli["INEQUALITY"]=="TOT"]
oecd_bli = oecd_bli.pivot(index="Country", columns="Indicator",
values="Value")
gdp_per_capita.rename(columns={"2017": "GDP per capita"}, inplace=True)
gdp_per_capita.set_index("Country", inplace=True)
full_country_stats = pd.merge(left=oecd_bli, right=gdp_per_capita,
left_index=True, right_index=True)
return full_country_stats[["GDP per capita", 'Life satisfaction']]

country_stats = prepare_country_stats(oecd_bli, gdp_per_capita)
#regularization remove_indices = [0, 1, 6, 8, 33, 34, 35]
country_stats.to_csv('country_stats.csv',encoding='utf-8')
X = np.c_[country_stats["GDP per capita"]]
Y = np.c_[country_stats["Life satisfaction"]]

#Visualize the data
country_stats.plot(kind='scatter',x='GDP per capita',y='Life satisfaction')

#Select a linear model
lin_reg_model = sklearn.linear_model.LinearRegression()

#Train the model
lin_reg_model.fit(X, Y)

#plot Regression model
t0, t1 = lin_reg_model.intercept_[0], lin_reg_model.coef_[0][0]
X = np.linspace(0, 110000, 1000)
plt.plot(X, t0 + t1 * X, "k")
plt.show()

#Make a prediction for Cyprus
X_new=[[22587]]
print(lin_reg_model.predict(X_new))
```