最近在看<Python变成:从入门到实践>书中的17章 使用Web Api
17.2.3 根据数据绘图
# coding=utf-8 import requests import pygal from pygal.style import LightColorizedStyle as LCS, LightenStyle as LS # 执行API调用并存储响应 URL = 'https://api.github.com/search/repositories?q=language:python&sort=star' r = requests.get(URL) print("Status code:", r.status_code) # 将API响应存储在一个变量中 response_dict = r.json() print("Total repositories:", response_dict['total_count']) # 研究有关仓库的信息 repo_dicts = response_dict['items'] print "Number of items:",len(repo_dicts) 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'], 'xlink':repo_dict['html_url'] } plot_dicts.append(plot_dict) else: plot_dict={'value':repo_dict['stargazers_count'], 'label':'ABC', 'xlink':repo_dict['html_url']} plot_dicts.append(plot_dict) # 可视化 my_style = LS('#333366', base_style=LCS) chart = pygal.Bar(style=my_style, x_label_rotation=45, show_legend=False) chart.title = 'Most-Starred Python Projects on GitHub' chart.x_labels = names chart.add('', plot_dicts) print plot_dicts chart.render_to_file('python_repos.svg')
上面的代码和书中有些不同,主要是
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'], 'xlink':repo_dict['html_url'] } plot_dicts.append(plot_dict) else: plot_dict={'value':repo_dict['stargazers_count'], 'label':'ABC', 'xlink':repo_dict['html_url']} plot_dicts.append(plot_dict)
为什么加上这段?
按书上的写法,出现如下报错
Traceback (most recent call last): File "C:/Users/vivi01.zhu/PycharmProjects/untitled2/python_repos.py", line 32, in <module> chart.render_to_file('python_repos.svg') File "C:\Python27\lib\site-packages\pygal\graph\public.py", line 114, in render_to_file f.write(self.render(is_unicode=True, **kwargs)) File "C:\Python27\lib\site-packages\pygal\graph\public.py", line 52, in render self.setup(**kwargs) File "C:\Python27\lib\site-packages\pygal\graph\base.py", line 217, in setup self._draw() File "C:\Python27\lib\site-packages\pygal\graph\graph.py", line 933, in _draw self._plot() File "C:\Python27\lib\site-packages\pygal\graph\bar.py", line 146, in _plot self.bar(serie) File "C:\Python27\lib\site-packages\pygal\graph\bar.py", line 116, in bar metadata) File "C:\Python27\lib\site-packages\pygal\util.py", line 233, in decorate metadata['label']) File "C:\Python27\lib\site-packages\pygal\_compat.py", line 61, in to_unicode return string.decode('utf-8') AttributeError: 'NoneType' object has no attribute 'decode'
需要显示在图上的plot_dicts可以打印出来,且正常
猜测是因为其中有个参数(repo_dict的description)为none,无属性,对此参数加上是否为none的if--else判断,运行通过,bingo~
('Status code:', 200) ('Total repositories:', 1923446) Number of items: 30 [{'xlink': u'https://github.com/vinta/awesome-python', 'value': 38175, 'label': u'A curated list of awesome Python frameworks, libraries, software and resources'}.................{'xlink': u'https://github.com/drduh/macOS-Security-and-Privacy-Guide', 'value': 11824, 'label': u'A practical guide to securing macOS.'}] Process finished with exit code 0