pythonpandaspandas-styles

DataFrame Styling based on conditions for groups of columns


I need to style a Dataframe:

df = DataFrame({'A':['Bob','Rob','Dob'],'B':['Bob', 'Rob','Dob'],'C':['Bob','Dob','Dob'],'D':['Ben','Ten','Zen'],'E':['Ben','Ten','Zu']})
df
     A  B    C  D   E
0   Bob Bob Bob Ben Ben
1   Rob Rob Dob Ten Ten
2   Dob Dob Dob Zen Zu

I need to compare columns - A,B, C at once to check if they are equal and then apply a highlight/color to unequal values. Then I need to compare columns D,E to check if they are equal and then apply a highlight/color to unequal values

like:

df[['A','B','C']].eq(df.iloc[:, 0], axis=0)

     A       B       C
0   True    True    True
1   True    True    False
2   True    True    True

I am unable to apply df.style with a subset of df and then concat.

Response to answer by @jezrael: enter image description here


Solution

  • I believe need:

    def highlight(x):
        c1 = 'background-color: red'
        c2 = '' 
        #define groups of columns for compare by first value of group ->
        #first with A, second with D
        cols = [['A','B','C'], ['D','E']]
    
        #join all masks together
        m = pd.concat([x[g].eq(x[g[0]], axis=0) for g in cols], axis=1)
        df1 = pd.DataFrame(c2, index=x.index, columns=x.columns)
        df1 = df1.where(m, c1)
        return df1
    
    df.style.apply(highlight, axis=None)
    

    pic

    EDIT: For multiple colors is possible create dictionary by colors with columns for compare:

    def highlight(x):
        c = 'background-color: '
        cols = {'red': ['A','B','C'], 'blue':['D','E']}
    
        m = pd.concat([x[v].eq(x[v[0]], axis=0).applymap({False:c+k, True:''}.get) 
                       for k, v in cols.items()], axis=1)
        return m
    

    pic2

    EDIT1:

    Alternative solution:

    def highlight(x):
        c = 'background-color: '
        cols = {'red': ['A','B','C'], 'blue':['D','E']}
    
        df1 = pd.DataFrame(c, index=x.index, columns=x.columns)
    
        for k, v in cols.items():
            m = x[v].eq(x[v[0]], axis=0).reindex(columns=x.columns, fill_value=True)
            df1 = df1.where(m, c+k)
        return df1    
    
    df.style.apply(highlight, axis=None)