Saving a data frame with a column of list in python

Question

I have a data frame a below:

   PT       CA        DE         AP
   0         1         2        [3,4,5,6]
   1         4         6        [7,8,9]

when I save this data frame and read it again, the 'AP' column is stored as string:

   PT       CA        DE         AP
   0         1         2       '(3,4,5,6)'
   1         4         6        '(7,8,9)'

When I try to change it to integer by the following command, I got an error:

df.AP = df.apply(lambda r: [int(r.AP[j]) for j in range(len(r.AP))], axis = 1)

Error:

("invalid literal for int() with base 10: '('", 'occurred at index 0')

Could you please tell me how can I solve this issue?

could you pls paste your saved text file here as well ? It look like that there is a parentheses in your file. — Enix
– Enix, Commented Oct 24, 2016 at 1:23

Enix · Accepted Answer · 2016-10-24 02:33:13Z

1

Your AP column is tuple quoted in a string, so can't convert to list directly. Try this:

ap = r.AP.replace('(', '').replace(')', '').split(',')
df.AP = df.apply(lambda r: [int(ap[j]) for j in range(len(ap)], axis = 1)

answered Oct 24, 2016 at 2:33

Enix

4,5991 gold badge26 silver badges37 bronze badges

Sign up to request clarification or add additional context in comments.

1 Answer 1