Add A Tuple To A Specific Cell Of A Pandas Dataframe

Just when I thought I was getting the hang of Python and Pandas, another seemingly simple issue crops up. I want to add tuples to specific cells of a pandas dataframe. These tuples

Solution 1:

You can use set_value:

tempDF.set_value(i,'newTuple', anyOldTuple)

Also make sure that the column is not a float column, for example:

tempDF['newTuple'] = 's' # or set the dtype

otherwise you will get an error.

Solution 2:

set_value is deprecated.

you can just use .at[] or iat[]

e.g. some_df.at[ idx, col_name] = any_tuple

Solution 3:

As J.Melody pointed out, .at[] and .iat[] can be used to assign a tuple to a cell, if the dtype of the column is object.

Minimal example:

df initialized as:
   a  b  c
0  0  1  2
1  3  4  5
2  6  7  8

df containing tuple:
   a       b  c
0  0  (1, 2)  2
1  3       4  5
2  6       7  8

Code:

import numpy as np
import pandas as pd

df = pd.DataFrame(np.arange(9).reshape((3,3)), columns=list('abc'), dtype=object)
print('df initialized as:', df, sep='\n')
df.at[0,'b'] = (1,2)
print()
print('df containing tuple:', df, sep='\n')

Note:

If you skip , dtype=object, you end up with

ValueError: setting an array element with a sequence.