Why does not work styling in Pandas Excel? :     import pandas as pd
    import xlsxwriter
    from datetime import datetime
    import sys
    				
    path = sys.argv[1]
    xl = pd.ExcelFile(path)
    df = xl.parse("Sheet1")
    df.columns = ['Nume', 'Tip de', 'Unit', 'Speciale Price', 'Suma de', 'Suma']


    def highlight_max(x):
    	return ['background-color: yellow' if v == x.max() else ''
    		for v in x]
    
    df.style.apply(highlight_max)
    df.loc[-1] = ['Totul', '', '', '', df['Suma de'].sum(), df['Suma'].sum()]

I tried to apply `highlight_max` to columns