Python程序的代码覆盖率的工具----Coverage to

最近写Python的测试代码需要用到代码覆盖率，

Coverage安装

$ python -m pip install coverage

除了使用命令行，还可以在python代码中直接调用coverage模块执行代码覆盖率的统计。使用方法也非常简单：

客户端案例代码hello.py

# coding=utf-8
from tornado.web import RequestHandler, Application
import tornado.ioloop
class MainHandler(RequestHandler):
    def get(self):
        self.write("Hello, world")
class PostMainHandler(RequestHandler):
    def post(self):
        self.write( "Post arg1: %s, arg2: %s"% (self.get_argument("arg1",""), self.get_argument("arg2","")))
application = Application([
    (r"/", MainHandler),(r"/post", PostMainHandler),
])
if __name__ == "__main__":
    application.listen(8888)
    tornado.ioloop.IOLoop.current().start()

服务器端代码test.py

# coding=utf-8
import unittest
from tornado.testing import AsyncHTTPTestCase
from hello import application
import coverage


class TestMain(AsyncHTTPTestCase):
    def get_app(self):
        return application

    def test_main(self):
        response = self.fetch('/')
        print(response.body)
        self.assertEqual(response.code, 200)
        self.assertEqual(response.body, b'Hello, world')
    def test_post(self):
        cov = coverage.coverage(branch=True)
        cov.start()
        response = self.fetch("/post", method="POST", body="arg1=foo&arg2=bar")
        print(response.body)
        self.assertEqual(response.code, 200)
        self.assertEqual(response.body, b"Post arg1: foo, arg2: bar")
        cov.stop()
        cov.report(skip_empty=True)
        cov.html_report(directory="test-html-result")
        #cov.xml_report(outfile="./testresult.xml")

if __name__ == '__main__':
    unittest.main()

结果展示

参数介绍

run() – 运行Python程序并且收集执行数据
report() – 报告覆盖率结果
html() – 生成覆盖率结果的HTML列表且带注释
xml() – 生成一份覆盖率结果的XML报告
annotate() – 使用覆盖结果注释源文件
erase() – 擦除以前收集的覆盖率数据
combine() – 将许多数据文件组合在一起
debug() – 获取诊断信息

参考文献：

[1] coverage-5.0.3官方文档