các ứng dụng web bằng cách chọn và cấu hình một chồng trung gian có logic boilerplate của ứng dụng ra khỏi con đường. Các khuôn khổ Python web là rất quan trọng để phát triển web hiện đại. Họ xử lý nhiều của logic của HTTP, và họ cũng cung cấp một số khái niệm trừu tượng quan trọng: | CHAPTER 11 WEB APPLICATIONS web applications by selecting and configuring a middleware stack that got the application s boilerplate logic out of the way. Python web frameworks are crucial to modern web development. They handle much of the logic of HTTP and they also provide several important abstractions they can dispatch different URLs to different Python code insert Python variables into HTML templates and provide important assistance in both persisting Python objects to the database and also in letting them be accessed from the web both through user-facing CRUD interfaces as well as RESTful web-service protocols. There do exist pure-Python web servers which can be especially important when writing a web interface for a program that users will install locally. There are not only good choices available for download but a few small servers are even built into the Python Standard Library. Two old approaches to dynamic web page generation are the CGI protocol and the mod_python Apache module. Neither should be used for new development. 196 C H A P T E R 12 E-mail Composition and Decoding The early e-mail protocols were among the first network dialects developed for the Internet. The world was a simple one in those days everyone with access to the Internet reached it through a command-line account on an Internet-connected machine. There at the command line they would type out e-mails to their friends and then they could check their in-boxes when new mail arrived. The entire task of an email protocol was to transmit messages from one big Internet server to another whenever someone sent mail to a friend whose shell account happened to be on a different machine. Today the situation is much more complicated not only is the network involved in moving e-mail between servers but it is often also the tool with which people check and send e-mail. I am not talking merely about webmail services like Google Mail those are really just the modern versions of the command-line shell
