I'm looking for a combination of two DataFrame structures in Python using a (shared) index value column.

Data snippet: 

```
d1 = {'col1': ['entry1', 'entry2', 'entry3'], 'col2': [1, 2,3]}
df1 = pd.DataFrame(data=d1)

d2= {'col1': ['entry2', 'entry3', 'entry1'], 'priority': [4, 2 , 7]}
df2 = pd.DataFrame(data=d2)

```

The result should be something like

```
col1     col2    priority  
----     ----    ----
entry1   1       7
entry2   2       4
entry3   3       2

```

How can I achieve that?