Pandas example calculate statistics metrics

import pandas

df = pandas.read_csv('Life_expectancy_at_birth_male_years.csv', skiprows=4, index_col=[0,1,2,3])
df.fillna(0,inplace=True)
df.drop(df.columns[len(df.columns)-1], axis=1, inplace=True)

modes   = []
medians = []
stds    = []
for buf_index, buf_value in df.iterrows():
    modes.append(buf_value.mean())
    medians.append(buf_value.median())
    stds.append(buf_value.std())

df['mode']   = modes
df['median'] = medians
df['std']    = stds

df.to_csv('out.csv')

print('done')