python - pandas: sum of each column results a NaN value? -

i have dataframe in pandas below. trying add row row-name ="total", sum of each column. using following code : df.loc["total"] = df.sum(axis =1)

i getting nan sum of each column. idea why , how solve ?

dataframe "total" row

use:

df.loc["total"] = df.sum() 

or if need convert first string values of columns float:

df.loc["total"] = df.astype(float).sum() 

sample:

df = pd.dataframe({'a':[1,2,3],                    'b':[4,5,6],                    'c':[7,8,9],                    'd':[1,3,5],                    'e':[5,3,6],                    'f':[7,4,3]})  print (df)     b  c  d  e  f 0  1  4  7  1  5  7 1  2  5  8  3  3  4 2  3  6  9  5  6  3  df.loc["total"] = df.sum() print (df)          b   c  d   e   f 0      1   4   7  1   5   7 1      2   5   8  3   3   4 2      3   6   9  5   6   3 total  6  15  24  9  14  14