The first part is similar to Constantine, you can get the boolean of which rows are empty*:
In [21]: ne = (df1 != df2).any(1)
In [22]: ne
Out[22]:
0 False
1 True
2 True
dtype: bool
Then we can see which entries have changed:
In [23]: ne_stacked = (df1 != df2).stack()
In [24]: changed = ne_stacked[ne_stacked]
In [25]: changed.index.names = ['id', 'col']
In [26]: changed
Out[26]:
id col
1 score True
2 isEnrolled True
Comment True
dtype: bool
Here the first entry is the index and the second the columns which has been changed.
In [27]: difference_locations = np.where(df1 != df2)
In [28]: changed_from = df1.values[difference_locations]
In [29]: changed_to = df2.values[difference_locations]
In [30]: pd.DataFrame({'from': changed_from, 'to': changed_to}, index=changed.index)
Out[30]:
from to
id col
1 score 1.11 1.21
2 isEnrolled True False
Comment None On vacation
* Note: it’s important that df1 and df2 share the same index here. To overcome this ambiguity, you can ensure you only look at the shared labels using df1.index & df2.index, but I think I’ll leave that as an exercise.