I want to merge 2 csv files. Resulting data frame column should have all the columns from csv 1.
For ex:

`df1 = pd.DataFrame({'name': ['foo', 'bar', 'baz', 'foo'],'value': [1, 2, 3, 5]})
df2 = pd.DataFrame({'class': ['a', 'b', 'c', 'd'],'value': [5, 6, 7, 8]})
df3 = pd.merge(df1, df2,how='outer')`

Result df3:
name value
foo 1
bar 2
baz 3
foo 5 
NaN 6 
NaN 7 
NaN 8 

How can i get the above result using joins?