import pandas as pd

df = pd.read_csv("http://www.info.univ-angers.fr/~richer/polytech/pimas_indians_diabetes.csv")

print("shape=", df.shape)
print(df.head()) 

remplacement = { 'tested_positive': 1, 'tested_negative': 0 }
df.replace( { 'class' : remplacement }, inplace=True)