1. Application Scenarios 1.1 Mail RFC821 requires that email content be ASCII. When a message contains other non-ASCII characters or binary data, Content-Transfer-Encoding is needed, and Base64 is one such method. 1.2 URL Some applications need to put binary data into a URL, but URLs only allow a specific set

1. Font-family The fonts you can use on a web page are limited to the handful of fonts already installed on the PC the browser is running on. Windows operating system, Chinese fonts: SimHei (Hei) SimSun (Song) NSimSun (New Song) FangSong (FangSong) KaiTi (Kai) FangSongGB2312 (FangSong GB2312) KaiTiGB2312 (Kai GB2312)

1. Basic Concepts Symmetric encryption: Symmetric encryption is an encryption method that uses a single-key cryptosystem, in which the same key is used both to encrypt and to decrypt the information. Because it is fast, it is often used to encrypt the transmission of large amounts of data. DES (Data

1. Introduction to Selenium Selenium is an integration testing tool from Thoughtworks. At its core, Selenium Core is based on JSUnit, written entirely in JavaScript, and can run in any browser that supports JavaScript. 1.1 Main Features and Characteristics Open source and free. Multi-browser support: Firefox, Chrome, IE, Opera — usable for compatibility testing.

1. Automatically Generating HTML Form Elements A Widget is the tool used to render an HTML element. Specifying a widget 1 2 3 4 5 6 from django import forms class CommentForm(forms.Form): name = forms.CharField() url = forms.URLField() comment = forms.CharField(widget=forms.Textarea) Output of CommentForm().as_table() 1 2 3 4 5 6