Question: If I try to see the suggestion of any word then its only giving me loading ..
can you please tell me whats the issue and how it can be fixed ?

I am not able to find out how to fix it.

Please help me if anyone know how to fix it.[Loading error image](https://i.stack.imgur.com/9oYhN.png)

Answer: 
Perform a FULL OUTER JOIN with `merge`, and remove the suffixes afterward.

```
u = left.merge(right, on=['key1', 'key2'], suffixes=('', '__2'), how='outer') 
u.columns = u.columns.str.replace('__2', '')

u
  key1 key2  valueX  valueY  valueX  valueY
0    A   a1     1.0     4.0     7.0    10.0
1    B   b1     2.0     5.0     NaN     NaN
2    C   c1     3.0     6.0     9.0    12.0
3    B   b2     NaN     NaN     8.0    11.0

```
You can merge with space as suffix and strip later

```
new_df = df1.merge(df2, on = ['key1', 'key2'], suffixes=(' ', ' '), how = 'outer')
new_df.columns = new_df.columns.str.strip()

    key1    key2    valueX  valueY  valueX  valueY
0   A       a1      1.0     4.0     7.0     10.0
1   B       b1      2.0     5.0     NaN     NaN
2   C       c1      3.0     6.0     9.0     12.0
3   B       b2      NaN     NaN     8.0     11.0

```