Flask学习笔记 7 - 日志和单元测试
Flask教程：http://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-vii-unit-testing
这次课首先添加了404.html和500.html错误页面；然后配置通过邮件和文件记录日志；用重复nickename为例讲了问题解决办法；最后写了个单元测试框架。
补充内容 最后添加了测试覆盖范围检查工具； Flash应用性能分析。
404和500错误页面
首先设置视图app/views.py
@app.errorhandler(404)
def not_found_error(error):
return render_template('404.html'), 404
@app.errorhandler(500)
def internal_error(error):
db.session.rollback()
return render_template('500.html'), 500
页面模板
- app/templates/404.html
{% extends "base.html" %}
{% block content %}
<h1>File Not Found</h1>
<p><a href="{{ url_for('index') }}">Back</a></p>
{% endblock %}
- app/templates/500.html
{% extends "base.html" %}
{% block content %}
<h1>An unexpected error has occurrred</h1>
<p>The administrator has been notified. Sorry for the inconvenience!</p>
<p><a href="{{ url_for('index') }}">Home</a></p>
{% endblock %}
日志邮件和日志文件
添加打开用户页面的链接__init__.py：
from config import basedir, ADMINS, MAIL_SERVER, MAIL_PORT, MAIL_USERNAME, MAIL_PASSWORD
if not app.debug:
import logging
from logging.handlers import SMTPHandler
from logging.handlers import RotatingFileHandler
credentials = None
if MAIL_USERNAME or MAIL_PASSWORD:
credentials = (MAIL_USERNAME, MAIL_PASSWORD)
mail_handler = SMTPHandler((MAIL_SERVER, MAIL_PORT), 'no-reply@' + MAIL_SERVER, ADMINS, 'microblog failure', credentials)
file_handler = RotatingFileHandler('tmp/microblog.log', 'a', 1*1024*1024, 10)
file_handler.setFormatter(logging.Formatter('%(asctime)s %(levelname)s: %(message)s [in %(pathname)s:%(lineno)d]'))
app.logger.setLevel(logging.INFO)
mail_handler.setLevel(logging.ERROR)
file_handler.setLevel(logging.INFO)
app.logger.addHandler(mail_handler)
app.logger.addHandler(file_handler)
app.logger.info('microblog startup')
当在run.py中设置
app.run(debug=False)，出现错误不会输出给客户（浏览器）。
[NOTE] 使用python的smtp模块把发送邮件在控制台中输出：
python -m smtpd -n -c DebuggingServer localhost:25
解决nickname重复的问题
在app/views.py的after_login中添加nickname = User.make_unique_nickname(nickname)：
if user is None:
nickname = resp.nickname
if nickname is None or nickname == "":
nickname = resp.email.split('@')[0]
nickname = User.make_unique_nickname(nickname)
user = User(nickname = nickname, email = resp.email)
db.session.add(user)
db.session.commit()
为用户类中添加make_unique_nickname(nickname)。 app/models.py
class User(db.Model):
# ...
@staticmethod
def make_unique_nickname(nickname):
if User.query.filter_by(nickname=nickname).first() is None:
return nickname
version = 2
while True:
new_nickname = nickname + str(version)
if User.query.filter_by(nickname=new_nickname).first() is None:
break
version += 1
return new_nickname
# ...
对于用户配置文件编辑页面中，如果用户自己输入的用户已经存在，那么给出重新输入提示。主要是覆写表单验证方法 app/forms.py
from app.models import User
class EditForm(Form):
nickname = StringField('nickname', validators=[DataRequired()])
about_me = TextAreaField('about_me', validators=[Length(min=0, max=140)])
def __init__(self, original_nickname, *args, **kwargs):
Form.__init__(self, *args, **kwargs)
self.original_nickname = original_nickname
def validate(self):
if not Form.validate(self):
return False
if self.nickname.data == self.original_nickname:
return True
user = User.query.filter_by(nickname=self.nickname.data).first()
if user != None:
self.nickname.errors.append('This nickname is already in use. Please choose another one.')
return False
return True
记得更新编辑页面的视图设置app/views.py
@app.route('/edit', methods=['GET', 'POST'])
@login_required
def edit():
form = EditForm(g.user.nickname)
# ...
更新编辑页面模板，显示错误信息。app/templates/edit.html
<td>Your nickname:</td>
<td>
{{ form.nickname(size=24) }}
{% for error in form.errors.nickname %}
<br><span style="color: red;">[{{ error }}]</span>
{% endfor %}
</td>
单元测试
#!flask/bin/python
import os
import unittest
from config import basedir
from app import app, db
from app.models import User
class TestCase(unittest.TestCase):
def setUp(self):
app.config['TESTING'] = True
app.config['WTF_CSRF_ENABLED'] = False
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + os.path.join(basedir, 'test.db')
self.app = app.test_client()
db.create_all()
def tearDown(self):
db.session.remove()
db.drop_all()
def test_avatar(self):
u = User(nickname='john', email='john@example.com')
avatar = u.avatar(128)
expected = 'http://www.gravatar.com/avatar/d4c74594d841139328695756648b6bd6'
assert avatar[0:len(expected)] == expected
def test_make_unique_nickname(self):
u = User(nickname='john', email='john@example.com')
db.session.add(u)
db.session.commit()
nickname = User.make_unique_nickname('john')
assert nickname != 'john'
u = User(nickname=nickname, email='susan@example.com')
db.session.add(u)
db.session.commit()
nickname2 = User.make_unique_nickname('john')
assert nickname2 != 'john'
assert nickname2 != nickname
if __name__ == '__main__':
unittest.main()
运行单元测试flask/Scripts/python tests.py，如果测试用例都通过，显示类似这样：
$ flask/bin/python test.py
..
----------------------------------------------------------------------
Ran 2 tests in 0.057s
OK
测试范围覆盖
查看这里的Test Coverage部分。
应用性能分析
查看这里的Profiling for performance部分。
Python自带了性能分析工具cProfile Flask有一个扩展为其提供应用性能分析Werkzeug 使用下面的profile.py替换run.py，启动应用就可以获得应用分析报表了。
#!flask/bin/python
from werkzeug.contrib.profiler import ProfilerMiddleware
from app import app
app.config['PROFILE'] = True
app.wsgi_app = ProfilerMiddleware(app.wsgi_app, restrictions=[30])
app.run(debug = True)