Pandas Change Value / Add Column

import pandas as pd items = [  {'name': 'Desmond', 'rank': 1},  {'name': 'Jack', 'rank': 2},  {'name': 'Elon', 'rank': 3}]df = pd.DataFrame(items) 

for index, row in df.iterrows():  df['rank'][index] = row['rank'] + 100

SettingWithCopyWarning: 
A value is trying to be set on a copy of a slice from a DataFrame

See the caveats in the documentation: https://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy

for index, row in df.iterrows():  df.at[index, 'rank'] = row['rank'] + 100

for index, row in df.iterrows():  df.at[index, 'rank2'] = row['rank'] + 100