Answers for "df merge pandas"

pandas merge python

import pandas as pd
df1 = pd.DataFrame({'lkey': ['foo', 'bar', 'baz', 'foo'],
                    'value': [1, 2, 3, 5]})
df2 = pd.DataFrame({'rkey': ['foo', 'bar', 'baz', 'foo'],
                    'value': [5, 6, 7, 8]})
df1.merge(df2, left_on='lkey', right_on='rkey')

joins in pandas

pd.merge(product,customer,how='inner',left_on=['Product_ID','Seller_City'],right_on=['Product_ID','City'])

merge dataframe pandas

>>> df1.merge(df2, left_on='lkey', right_on='rkey')
  lkey  value_x rkey  value_y
0  foo        1  foo        5
1  foo        1  foo        8
2  foo        5  foo        5
3  foo        5  foo        8
4  bar        2  bar        6
5  baz        3  baz        7

merge pandas

select * from bricks;

select * from colours;

merge pandas

create table bricks (
  brick_id integer,
  colour   varchar2(10)
);

create table colours (
  colour_name           varchar2(10),
  minimum_bricks_needed integer
);

insert into colours values ( 'blue', 2 );
insert into colours values ( 'green', 3 );
insert into colours values ( 'red', 2 );
insert into colours values ( 'orange', 1);
insert into colours values ( 'yellow', 1 );
insert into colours values ( 'purple', 1 );

insert into bricks values ( 1, 'blue' );
insert into bricks values ( 2, 'blue' );
insert into bricks values ( 3, 'blue' );
insert into bricks values ( 4, 'green' );
insert into bricks values ( 5, 'green' );
insert into bricks values ( 6, 'red' );
insert into bricks values ( 7, 'red' );
insert into bricks values ( 8, 'red' );
insert into bricks values ( 9, null );

commit;

pandas merge dataframes

import pandas as pd
pd.merge(restaurant_ids_dataframe, restaurant_review_frame, on='business_id', how='outer')