Python Pandas - highlighting cells in a dataframe

Question

I would like to test if the values of a column are bigger than another specific value of the same data frame. If a value is bigger, I want to highlight this specific cell.

I tried this:

import pandas as pd

b = pd.DataFrame([[5,7,3],[2,3,4],[8,4,7]])

for i in range(0, len(b)):
    for j in range(0, len(b.columns)):
        if  b.iloc[i][j] >  b.iloc[2][j]:
            b.style.applymap(lambda  x: 'background-color : blue' if b.iloc[i][j] >  b.iloc[2][j] else '') 

b

So in this example I want to check if 5 or 7 is bigger than 3 (column 1), 2 or 3 bigger than 4 (column 2) and 8 or 4 is bigger than 7.

It doesn't color anything... I hope someone can help me. Thx in advance.

Answer 1

Try this solution:

import pandas as pd
import numpy as np

df = pd.DataFrame([[5,7,8],[2,3,4],[8,4,9]])

def highlight(s):
    '''
    highlight the maximum in a Series.
    '''
    is_max = s >= s[2]
    return ['background-color: blue' if v else '' for v in is_max]

df.style.apply(highlight, axis=0)

Note that the solution is based on the thread we discussed. The main change is the condition inside the highlight function. Using applymap works on a single cell each time, and has no access to its location in the dataframe. Using apply works on a single row each time and enables comparing to cell in the same row and different column.