Potential bug/Unspecified behaviour

Let's look at a template like this:

http://example.com/dictionary/{term:1}

We have two different behaviours depending upon the value used to expand term.

>>> import uritemplate
>>> u = uritemplate.URITemplate('http://example.com/dictionary/{term:1}')
>>> u.expand(term='foo')
'http://example.com/dictionary/f'
>>> u.expand(term=['foo', 'bar', 'bogus'])
'http://example.com/dictionary/foo,bar,bogus'

A simplified version of this is simply

{term:1}

In other words:

>>> import uritemplate
>>> u = uritemplate.URITemplate('{term:1}')
>>> u.expand(term='foo')
'f'
>>> u.expand(term=['foo', 'bar', 'bogus'])
'foo,bar,bogus'

All versions of uritemplate (and uritemplate.py) exhibit this behaviour and the RFC does not provide clear guidance.

I have not investigated how other implementations in other languages handle this, though. There do not appear to be any examples in the RFC that combine lists with length limitations.

先从 issue 中的 URITemplate.expand 示例和 RFC 6570 的前缀修饰符规则开始，然后比较标量和值列表的展开方式。该 issue 没有指定 repository 文件或现有测试；完成应意味着对列表值达成一致的解释，并为两种形式提供回归覆盖。