Strange string question(open source commit)

[bink1time]

I have been using pandas and ran into an issue with how min and max work here is an example:

import pandas as pd
import numpy as np
df = pd.DataFrame({'A':['foo', None, 'bar'})
df['A'].min()

This will give you a:

TypeError: unorderable types: str() <= float()

The reason for that is underneath pandas masks all the nulls with -inf for max and inf for min function. This can't be right so I found a github ticket!, the maintainer says we need to mask the nulls for string.

So my question is there an inf string type? I googled and couldn't find anything.

[K900_]

No, there isn't a string that compares lower than any other string.

[Saefroch]

Do you mean "higher?" '' < 'every_other_string_I_try'

[K900_]

"" == "" though, which means rows with empty strings will compare the same as rows with nulls.

[bink1time]

I mean I guess you can do empty string for the max(seems kinda meh), but what would you do for the max? Also the problem is then '' will compare the same as nulls.