“DataFram Combine 3 columnas a DateTime” Código de respuesta

DataFram Combine 3 columnas a DateTime

from datetime import datetime
df['date']= df.apply(lambda x:datetime.strptime("{0} {1} {2}".format(x['year'],x['month'], x['day']), "%Y %m %d"),axis=1)
df.index= df['date']