Merging two non-overlapping pandas dataframe columns

I have a pandas dataframe with a pair of columns where, on every row, one cell is a nan and the other is not. It looks like this:

	Var1	Var2
0	3	nan
1	8	nan
2	nan	6
3	4	nan
4	nan	2
5	nan	6

I would like to merge these two columns in one without the nans:

	Var1
0	3
1	8
2	6
3	4
4	2
5	6

Any ideas?

Answer

Use fillna, setting values parameter to another Series.

df['Var1'].fillna(df['Var2'], inplace=True)
df['Var1']

#    Var1
# 0  3
# 1  8
# 2  6
# 3  4
# 4  2
# 5  6