试验了一下python的urllib库以及js 的 encodeURIComponent 均不会替换。空格encode也是替换成了 '%20' 。python提供了urllib.quote_plus,urlib.unquote_plus来处理空格->加号，看起来还是比较合理的。 查了一下 RFC 3986: 有下面一段 Scheme names consist of a sequence of characters beginning with a letter and followed by any combination of letters,digits,plus ("+"),period ("."),or hyphen ("-").
RFC 2396 有下面的一段 The plus "+",dollar "$",and comma "," characters have been added to those in the "reserved" set,since they are treated as reserved within the query component.
表示加号已经是url的保留字了，不需要转义。 然后html4文档里才有关于加号的转义： application/x-www-form-urlencoded
Forms submitted with this content type must be encoded as follows:
Control names and values are escaped. Space characters are replaced by`+',and then reserved characters.....
声明只有content-type为application/x-www-form-urlencoded时才会对+做转义。 又翻了下PHP的文档，发现有一个 rawurlencode() - URL-encode according to RFC 3986
也就是PHP又搞了rawurlencode和rawurldecode把标准实现了。。。。 不能反一下么，毕竟大部分人应该都会用urlencode。PHP真是蛋疼啊。。。。