Get the name of columns from rows distinct from zero python

I have this dataframe:

df0 = pd.DataFrame({'points': [0, 0, -3, 16, 0, 5, -3, 14],
                    'assists': [0, 0, 2, 0, 1, -7, 0, 6],
                    'numbers': [0, 0, 1, 6, 10, 5, 8, 7]})

and my desired dataset looks like this:

points assists numbers colX
0      0       0        0
0      0       0        0
-3     2       1       'points-assists-numbers'
16     0       6       'points-numbers'
0      1       10      'assists-numbers'
5      7       5       'points-assists-numbers'
-3     0       8       'points-numbers'
14     8       7       'points-assists-numbers'

A function that create a string from columns names that have values distinct from zero.

Any help?

>Solution :

This kind of operation is well suited to a lambda expression.

Something like this should work:

df0['colX'] = df0.apply(lambda x: '-'.join(c for c in df0.columns if x[c] != 0), axis=1).replace('', 0)

• first it gets a list of the columns that are not 0
• joins the names of those columns with a "-"
• after that, fills blank names with a 0