Python:为什么 “~” 现在包含在 urllib.parse.quote() 的保留字符集中？

Question

最recent documentation for urllib状态:

Changed in version 3.7: Moved from RFC 2396 to RFC 3986 for quoting URL strings. “~” is now included in the set of reserved characters.

为什么会这样？在 RFC 3986 , ~ 不是保留字符:

 reserved    = gen-delims / sub-delims

 gen-delims  = ":" / "/" / "?" / "#" / "[" / "]" / "@"

 sub-delims  = "!" / "$" / "&" / "'" / "(" / ")"
             / "*" / "+" / "," / ";" / "="

明确在 the next section 中它作为非保留字符包含在内:

2.3. Unreserved Characters

Characters that are allowed in a URI but do not have a reservedpurpose are called unreserved. These include uppercase and lowercaseletters, decimal digits, hyphen, period, underscore, and tilde.

 unreserved  = ALPHA / DIGIT / "-" / "." / "_" / "~"

此外，later on ，RFC 指出(强调我的):

For example, the octet corresponding to the tilde ("~") character is often encoded as "%7E" by older URI processing implementations;

所以看起来 3.7 是不一致的:它断言支持更新的 RFC，同时回归 ~ 的处理。 (事实上​​ ，在 older RFC 中， ~ 也没有被保留，也没有 ' unwise ')

Answer 1

此错误已在 https://bugs.python.org/issue16285 中跟踪并关闭

事实上，最新版本的代码反射(reflect)了这些变化。

引用 https://github.com/python/cpython/blob/master/Lib/urllib/parse.py

_ALWAYS_SAFE = frozenset(b'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
                     b'abcdefghijklmnopqrstuvwxyz'
                     b'0123456789'
                     b'_.-~')