How do I fix this error?

#importing the libraries import pandas as pd import numpy as np #reading the dataset df=pd.read_csv ("Salary.csv") print (df.info) # Import label encoder from sklearn import preprocessing # label_encoder object knows how to understand word labels. label encoder = preprocessing.LabelEncoder ( ) # Encode labels in column 'Country'. data['Country']= label_encoder.fit_transform(data['Country']) print (data.head() ) Country Age Salary NameError Traceback (most recent call last) in 12 label_encoder = preprocessing. LabelEncoder() 13 # Encode labels in column 'Country' 14 data[ 'Country']= label_encoder.fit_transform(data['Country']) 15 print (data.head()) NameError: name 'data' is not defined