python pandas dataframe mutate all elements as (element / max element in row)

Question

df=

x1, x2, x3, x4, x5...x90, \'ignore\'
37.4, 35.6, 43.5, 33.3, 42.4...42.5, \'ignoe\'
32.2, 37.2, 43.4, 34.3, 82.4...22.1, 44
33.5, 45.5, 25.9, 23.8, 24.2...52.