[pandas DataFrame Correlation Matrix with Colored Entries] Remove lower-tri elements, make large numbers red #python #pandas #color #DataFrame

pandas Colored Corr.py

def color_large_value_red(val):
    """
    Takes a scalar and returns a string with
    the css property `'color: red'` for absolute values > 0.5,
    black otherwise.
    """
    
    try:
        float_val = float(val)
        color = 'red' if (abs(float_val) > 0.4) and (float_val != 1) else 'black'
        
    except:
        color = 'black'
    
    return 'color: %s' % color
    
    
vars_to_corr = [
    'var1', 'var2', 
]

df_corr = df[vars_to_corr].corr().round(decimals=3).astype(str)

df_corr.values[np.tril_indices(df_corr.shape[0], k=-1)] = ''

rename_func = lambda x: x.replace('what', 'to')

df_corr.rename(
    index=rename_func,
    columns=rename_func,
    inplace=True
)

df_corr.style.applymap(color_large_value_red)