Set value for particular cell in pandas DataFrame using index

Question

I\'ve created a Pandas DataFrame

df = DataFrame(index=[\'A\',\'B\',\'C\'], columns=[\'x\',\'y\'])

and got this

    x    y
A  NaN         


        

Answer 1

I too was searching for this topic and I put together a way to iterate through a DataFrame and update it with lookup values from a second DataFrame. Here is my code.

src_df = pd.read_sql_query(src_sql,src_connection)
for index1, row1 in src_df.iterrows():
    for index, row in vertical_df.iterrows():
        src_df.set_value(index=index1,col=u'etl_load_key',value=etl_load_key)
        if (row1[u'src_id'] == row['SRC_ID']) is True:
            src_df.set_value(index=index1,col=u'vertical',value=row['VERTICAL'])

Answer 2

To set values, use:

df.at[0, 'clm1'] = 0

• The fastest recommended method for setting variables.
• set_value, ix have been deprecated.
• No warning, unlike iloc and loc