Reshaping a pandas correlation matrix

Use the code below to (a) reshape the correlation matrix, (b) remove duplicate rows (e.g., {aaa, bbb} and {bbb, aaa}), and (c) remove rows that contain the same variable in the first two columns (e.g., {aaa, aaa}):

# calculate the correlation matrix and reshape
df_corr = df.corr().stack().reset_index()

# rename the columns
df_corr.columns = ['FEATURE_1', 'FEATURE_2', 'CORRELATION']

# create a mask to identify rows with duplicate features as mentioned above
mask_dups = (df_corr[['FEATURE_1', 'FEATURE_2']].apply(frozenset, axis=1).duplicated()) | (df_corr['FEATURE_1']==df_corr['FEATURE_2']) 

# apply the mask to clean the correlation dataframe
df_corr = df_corr[~mask_dups]

This will generate an output like this:

    FEATURE_1  FEATURE_2  CORRELATION
0         aaa        bbb     0.346099
1         aaa        ccc     0.131874
2         aaa        ddd    -0.150910
3         aaa        eee     0.177589
4         bbb        ccc     0.177308
5         bbb        ddd    -0.384893
6         bbb        eee     0.301150
7         ccc        ddd    -0.176995
8         ccc        eee     0.258812
9         ddd        eee    -0.310137

You need add reset_index:

#reset columns and index names 
df = df.rename_axis(None).rename_axis(None, axis=1)

#if pandas version below 0.18.0
#df.columns.name = None
#df.index.name = None

print (df)
          aaa       bbb       ccc       ddd       eee
aaa  1.000000  0.346099  0.131874 -0.150910  0.177589
bbb  0.346099  1.000000  0.177308 -0.384893  0.301150
ccc  0.131874  0.177308  1.000000 -0.176995  0.258812
ddd -0.150910 -0.384893 -0.176995  1.000000 -0.310137
eee  0.177589  0.301150  0.258812 -0.310137  1.000000
df1 = df.stack().reset_index()
#set column names
df1.columns = ['a','b','c']
print (df1)
      a    b         c
0   aaa  aaa  1.000000
1   aaa  bbb  0.346099
2   aaa  ccc  0.131874
3   aaa  ddd -0.150910
4   aaa  eee  0.177589
5   bbb  aaa  0.346099
6   bbb  bbb  1.000000
7   bbb  ccc  0.177308
8   bbb  ddd -0.384893
9   bbb  eee  0.301150
10  ccc  aaa  0.131874
11  ccc  bbb  0.177308
12  ccc  ccc  1.000000
13  ccc  ddd -0.176995
14  ccc  eee  0.258812
15  ddd  aaa -0.150910
16  ddd  bbb -0.384893
17  ddd  ccc -0.176995
18  ddd  ddd  1.000000
19  ddd  eee -0.310137
20  eee  aaa  0.177589
21  eee  bbb  0.301150
22  eee  ccc  0.258812
23  eee  ddd -0.310137
24  eee  eee  1.000000