brands.py

def create_links(df_rec, df_ordbr, list_brand):
    ''' Create links dataframe '''

    # Unique brands per order
    df_source = pd.DataFrame(df_rec.groupby(['ORDER_NUMBER'])['BRAND'].unique())
    df_source.columns = ['list_brand']
    
    list_source, list_target, list_value = [], [], []
    for br1 in list_brand:
        for br2 in list_brand:
            value = (df_ordbr[br1] * df_ordbr[br2]).sum()
            if value > 0:
                list_source.append(br1)
                list_target.append(br2)
                list_value.append(value)

    # Build links dataframe
    df_links = pd.DataFrame({
        'source': list_source,
        'target': list_target,
        'value':list_value
    })

    # Mapping with Brands ID
    dict_map = dict(zip(df_links['source'].unique(), [i for i in range(len(list_brand))]))
    for col in ['source', 'target']:
        df_links[col] = df_links[col].map(dict_map)
        
    return df_links