Pandas Concat Array Unorderable RuntimeWarning

Question

I have recently started learning pandas and I was trying to analyze the Stack Overflow developer survey. I am trying to learn the groupby function:

country_grp=df.groupby(['Country'])

country_grp.get_group('China')

ed=country_grp['EdLevel'].value_counts()

salary=country_grp['ConvertedComp'].value_counts()

response=country_grp['Country'].value_counts()

combine=pd.concat([ed,response,salary],axis='columns',sort=False)

combine

After this line it's giving me this warning:

 RuntimeWarning: The values in the array are unorderable. Pass
 `sort=False` to suppress this warning. uniq_tuples =
 lib.fast_unique_multiple([self._values, other._values], sort=sort)

It gives me the data frame but all the rows for ['country'] columns are NaN. Can someone please guide me how can I solve this?

Answer 1

I am not sure if the problem is the same as mine since there is no underlying data. I got a similar error, which was due to the data type of the indices index for each dataframe in the concat function being different, though it looks the same. After making all index data types the same, the warning and NaN disappear.