Модифицированная диаграмма Ганта

это мой самый первый код pandas / matplotlib, и я был бы благодарен, если вы ознакомитесь с моим кодом и поделитесь своими мыслями или идеями по улучшению. Пожалуйста, сосредоточьтесь на коде, а не на характеристиках полученной диаграммы. Спасибо за ваше мнение.

Цель кода — создать Диаграмма Ганта показаны мои планы на учебные курсы 2021 года. Входные данные здесь

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
from IPython.core.display import display, HTML
display(HTML("<style>.container { width:100% !important; }</style>")) # Resize notebook screen

df = pd.read_excel('test-data.xlsx')
df.dropna(how='all', inplace=True) # Drop empty lines
df['Duration'] = df['Duration'].fillna(1).astype(np.int32) # Replace missing duration with 1 (one hour) an change column type to integer
df['Category'] = df['Category'].fillna('Other') # Replace missing category name with Other
df['Start'] = df['Start'].fillna(min(df['Start'])) # Replace missing start time with min date
df['End'] = df['Start'] + df['Duration'] * pd.Timedelta(days=1) # Helper column with task end date

fig, ax = plt.subplots(figsize = (20, 20))
ax.axis('off')

# Today line
today = pd.Timestamp.today()
today_line_length = len(df) + len(df['Category'].unique()) * 4 + 6 # Number of tasks + 4 * number of groups + margins
ax.vlines(today, ymin=-3, ymax=today_line_length, color="yellow", lw=2, zorder=-1) # Draw vertical line on today's mark
ax.text(today, -3, today.date(), fontweight="bold")
ax.text(today, today_line_length + 1, today.date(), fontweight="bold")

# Quarters bars 
q = pd.date_range(min(df['Start']), freq='QS', periods=(max(df['End']) - min(df['Start'])).days//91+1)
for i, quarter in enumerate(q):
    if (i % 2 == 1) and (i<len(q)-1): ax.fill_between((q[i],q[i+1]), -5, today_line_length+2.5, facecolor="tab:cyan", alpha = 0.2)
    quarter_label="Q"+str(quarter.quarter)+'-'+str(quarter.year)
    ax.text(quarter + pd.DateOffset(days=45), -4, quarter_label, ha="center") # Display today's date on top
    ax.text(quarter + pd.DateOffset(days=45), today_line_length+2, quarter_label, ha="center") # Dsiplay today's date in bottom

ax.invert_yaxis() # y axis starts at top and ends in bottom
group_start_y = -1 # Where to start plotting first group 

# Main loop, for each group draw the group summary and all the tasks
for group in df.groupby('Category', sort=False): # Don't sort, by default i would be sorted alphabetically
    group_name = group[0] # Group name
    df_g = group[1] # Group dataframe
    group_size_y = len(df_g) + 1 # Count of group members + 1 row margin
    group_start_x = min(df_g['Start']).date() # Soonest date in the group
    group_end_x = max(df_g['End']).date() # Latest date in group (max start date + duration)
    
    
    # Display group name and summary  
    ax.text(group_start_x, group_start_y, group_name, size="large", fontweight="bold") # Group name
    group_duration_str = str(group_start_x) + ' to ' + str(group_end_x) # Group start and end date
    ax.text(group_start_x, group_start_y+1, group_duration_str) # Group duration
    ax.text(group_start_x, group_start_y+2, str(int(len(df_g[~df_g['Completed'].isnull()])/len(df_g) *100)) + '% completed') # Completion percentage
    group_start_y += 3 # Where to start with tasks
    ax.hlines(group_start_y + group_size_y - 0.5, xmin=min(df['Start']), xmax=max(df['End']), color="tab:grey", alpha=0.5)
    
    # Display each task
    for i, task_name in enumerate(df_g['Name']):
        task = df_g.iloc[i]
        
        # Get bar color
        task_color="tab:grey" # Planned
        if task['End'] < today: task_color="tab:red" # Overdue
        if task['Completed'] < today: task_color="tab:green"  # Completed     

        ax.broken_barh([(task['Start'],task['Duration'])],(group_start_y+i,1), color=task_color) # Draw bar
        ax.text(task['Start']+task['Duration'] * pd.DateOffset(days=1) + pd.DateOffset(days=2),group_start_y+i+0.6,task_name, va="center") # bar label - task name
        
    group_start_y += group_size_y + 1 # One row space between group end and start of another group 
plt.savefig('gantt.png', format="png") # Save chart to PNG

Приведенный выше код дает следующее изображение