Excel - charting with Python

I have an excel file having large no. of experiment data, each experiment data start with time column value 00:00:00., ending time is not same for all. I want plot of all experiment data in same graph

Currently I wrote a Python script, it is plotting well but i am facing with one issue that is, End point of first experiment is connected through a line with first point of second experiment which i do not want.

also when i was tried to plot every 5th experiment then color not changes of each experiment

I tried this code but it is not capable to resolve the issue

file_path = os.path.join(source_folder, file_name)

        df = pd.read_excel(file_path, sheet_name='record')  

        filtered_df = df[df.iloc[:, 3] == 'CC DChg']

        selected_columns = ['Time', 'Current(A)', 'Voltage(V)', 'Capacity(Ah)', 'Energy(Wh)']
        
        filtered_selected_df = filtered_df[selected_columns]
        
        start_indices = filtered_selected_df[filtered_selected_df['Time'] == '00:00:00'].index
        plt.figure(figsize=(8, 6))
        
        num_experiments = len(start_indices) 
        #colors = plt.cm.viridis(np.linspace(0, 1, num_experiments))
              
        for i in range(0, num_experiments):
            start_idx = start_indices[i]
            
            if i + 1 < num_experiments:
                end_idx = start_indices[i + 1]
            else:
                end_idx = len(filtered_selected_df)
                
            experiment_data = filtered_selected_df.iloc[start_idx:end_idx]
            
            if i != 0:
                experiment_data = pd.concat([pd.DataFrame({'Capacity(Ah)': [float('nan')], 'Voltage(V)': [float('nan')]}),
                                             experiment_data])
            
            plt.plot(experiment_data['Capacity(Ah)'], experiment_data['Voltage(V)'],marker='o', linestyle='-', 
                     label=f'cycle {i + 1}')
            plt.legend()
            
        plt.title(f'Voltage vs Capacity for {file_name}')
        plt.xlabel('Capacity(Ah)')
        plt.ylabel('Voltage(V)')
        plt.grid(True)
        plt.show()