Problem

Given this dataframe:

df = pd.DataFrame([[1, 2, 3], [4, 5, 6], [7, 8, 9]])

what is the simplest route to this:

        0       1       2
0  (1, 0)  (2, 0)  (3, 0)
1  (4, 0)  (5, 0)  (6, 0)
2  (7, 0)  (8, 0)  (9, 0)

Considered Questions and Approaches

Is there a way to convert the existing dataframe to a dataframe of tuples?

I haven't found a way to do so, nor thought of a better alternative, so my current approach is to create a new df, replacing each entry with a tuple (entry, flag).

In order to do that I would like to copy or add the original df to a df with empty tuples (0, 0), to avoid manually iterating over and reformating each entry into the new df.

Note, I would like to add the flag to each entry, not each row, making this question different from Adding binary flag to pandas DataFrame.

CodePudding user response：

Update

Actually, it seems we need to make it a list since tuples are immutable

Simple use applymap (cell by cell):

>>> df.applymap(lambda x: [x, 0])
        0       1       2
0  [1, 0]  [2, 0]  [3, 0]
1  [4, 0]  [5, 0]  [6, 0]
2  [7, 0]  [8, 0]  [9, 0]

Or apply with a comprehension:

>>> df.apply(lambda x: [[i, 0] for i in x])
        0       1       2
0  [1, 0]  [2, 0]  [3, 0]
1  [4, 0]  [5, 0]  [6, 0]
2  [7, 0]  [8, 0]  [9, 0]