从 2.5 版起弃用： 使用 hashlib 模块代替。
This module implements the interface to NIST’s secure hash algorithm, known as SHA-1. SHA-1 is an improved version of the original SHA hash algorithm. It is used in the same way as the md5 module: use new() to create an sha object, then feed this object with arbitrary strings using the update() method, and at any point you can ask it for the digest of the concatenation of the strings fed to it so far. SHA-1 digests are 160 bits instead of MD5’s 128 bits.
返回新 SHA 对象。若 string is present, the method call update(string) is made.
The following values are provided as constants in the module and as attributes of the sha objects returned by new() :
Size of the blocks fed into the hash function; this is always 1 . This size is used to allow an arbitrary string to be hashed.
The size of the resulting digest in bytes. This is always 20 .
SHA 对象拥有如 MD5 对象的相同方法：
Update the sha object with the string arg . Repeated calls are equivalent to a single call with the concatenation of all the arguments: m.update(a); m.update(b) 相当于 m.update(a+b) .
Return the digest of the strings passed to the update() method so far. This is a 20-byte string which may contain non-ASCII characters, including null bytes.
像 digest() except the digest is returned as a string of length 40, containing only hexadecimal digits. This may be used to exchange the value safely in email or other non-binary environments.
Return a copy (“clone”) of the sha object. This can be used to efficiently compute the digests of strings that share a common initial substring.
另请参阅
