【Pyhton】pygal資料可視化報錯：“AttributeError: 'NoneType' object has no attribute 'decode'”

錯誤來源：《Python程式設計：從入門到實踐》一書第17章第2節第3小節！

原書代碼:

import requests
import pygal
from pygal.style import LightColorizedStyle as LCS, LightenStyle as LS

#執行API調用并存儲響應
url = 'https://api.github.com/search/repositories?q=language:python&sort=stars'
result = requests.get(url)
print("status code:",result.status_code)

#将API響應存儲在一個變量中
response_dict = result.json()
print("Total reposeitories:",response_dict['total_count'])

# 研究有關倉庫的資訊
repo_dicts = response_dict['items']
print("Repositories returned:",len(repo_dicts))

names,plot_dicts = [],[]
for repo_dict in repo_dicts:
    names.append(repo_dict['name'])
  
    plot_dict = {
    'value':repo_dict['stargazers_count'],
    'label':repo_dict['description'],
    }
     plot_dicts.append(plot_dict)
    

#配置可視化圖形
my_style = LS('#8F4586',base_style=LCS)

my_config = pygal.Config()
my_config.x_label_rotation = 45
my_config.show_legend = False
my_config.title_font_size = 24
my_config.label_font_size = 14
my_config.major_label_font_size = 18
my_config.truncate_label = 15
my_config.show_y_guides = True   #是否顯示水準線
my_config.width = 1000           #圖表寬度

chart = pygal.Bar(my_config,style = my_style)
chart.title = 'Most-Starred Python Project on GitHub'
chart.x_labels = names

chart.add('',plot_dicts)
chart.render_to_file('pyhton_repos.svg')
           

代碼執行後報錯：

status code: 200

Total reposeitories: 2989171

Repositories returned: 30

Traceback (most recent call last):

  File "D:/PythonWorkstation/learning_path/day06/API/test.py", line 46, in <module>

    chart.render_to_file('pyhton_repos.svg')

  File "D:\python3\Anaconda3\lib\site-packages\pygal\graph\public.py", line 114, in render_to_file

    f.write(self.render(is_unicode=True, **kwargs))

 ***

AttributeError: 'NoneType' object has no attribute 'decode'

問題猜想：

可能是repo_dict的‘description’的參數為none，是以我們加入if--else來判斷一下。代碼如下：

names,plot_dicts = [],[]
for repo_dict in repo_dicts:
    names.append(repo_dict['name'])

    if repo_dict['description']:
        plot_dict = {
            'value':repo_dict['stargazers_count'],
            'label':repo_dict['description'],
        }
        plot_dicts.append(plot_dict)
    else:
        plot_dict = {
            'value':repo_dict['stargazers_count'],
            'label':'None'
        }
        plot_dicts.append(plot_dict)
           

再次運作：

status code: 200

Total reposeitories: 2989190

Repositories returned: 30

Process finished with exit code 0

來看看生成的圖形效果：