python - 为什么 urllib.urlencode 将 "25"附加到结果？

Question

Python代码是:

user = "aabc" 
password = "yyy12%"
data = urllib.urlencode({"loginname": user, "nloginpwd": password})
print data

结果是:loginname=aabc&nloginpwd=yyy12%25

为什么要在字符串末尾添加 25？

Answer 1

% 字符在 URL 中具有特殊含义；它用于启动转义序列。查看Percent-encoding article在维基百科上。 literal % 也必须进行编码，%25 是编码后的版本。来自维基百科页面:

Because the percent ("%") character serves as the indicator for percent-encoded octets, it must be percent-encoded as "%25" for that octet to be used as data within a URI.

换句话说，%25 是一个编码的 % 字符。