Suppose I have a DataFrame with MultiIndex columns. How can I collapse the levels to a concatenation of the values so that I only have one level?
np.random.seed([3, 14])
col = pd.MultiIndex.from_product([list('ABC'), list('DE'), list('FG')])
df = pd.DataFrame(np.random.rand(4, 12) * 10, columns=col).astype(int)
print df
A B C
D E D E D E
F G F G F G F G F G F G
0 2 1 1 7 5 9 9 2 7 4 0 3
1 3 7 1 1 5 3 1 4 3 5 6 0
2 2 6 9 9 9 5 7 0 1 2 7 5
3 2 2 8 0 3 9 4 7 0 8 2 5
I want the result to look like this:
ADF ADG AEF AEG BDF BDG BEF BEG CDF CDG CEF CEG
0 2 1 1 7 5 9 9 2 7 4 0 3
1 3 7 1 1 5 3 1 4 3 5 6 0
2 2 6 9 9 9 5 7 0 1 2 7 5
3 2 2 8 0 3 9 4 7 0 8 2 5
you may try this:
In [200]: cols = pd.Series(df.columns.tolist()).apply(pd.Series).sum(axis=1)
In [201]: cols
Out[201]:
0 ADF
1 ADG
2 AEF
3 AEG
4 BDF
5 BDG
6 BEF
7 BEG
8 CDF
9 CDG
10 CEF
11 CEG
dtype: object