AnyUrl does not recognize fragment without query string

[andrewmwhite]

Checks

• I added a descriptive title to this issue
• I have searched (google, github) for similar issues and couldn't find anything
• I have read and followed the docs and still think this is a bug

Bug

Output of python -c "import pydantic.utils; print(pydantic.utils.version_info())":

             pydantic version: 1.7.3
            pydantic compiled: True
                 install path: /Users/andwhite/Projects/lipy-sso_trunk/build/lipy-sso/environments/development-venv/lib/python3.7/site-packages/pydantic
               python version: 3.7.7 (default, Mar 10 2020, 16:11:21)  [Clang 11.0.0 (clang-1100.0.33.12)]
                     platform: Darwin-19.6.0-x86_64-i386-64bit
     optional deps. installed: ['typing-extensions']

RFC3986 indicates that a URI with a fragment but not a query is valid, but pydantic does not parse this correctly, instead treating the fragment as part of the path:

from pydantic import AnyUrl, BaseModel


class Model(BaseModel):
    v: AnyUrl


def test_url_fragment_without_query():
    url = Model(v='https://pydantic-docs.helpmanual.io/usage/types/#constrained-types').v
    assert url.query is None
    assert url.fragment == 'constrainted-types'

Pytest output:

=========================================== test session starts ===========================================
platform darwin -- Python 3.7.7, pytest-5.3.5, py-1.8.1, pluggy-0.13.1
hypothesis profile 'default' -> database=DirectoryBasedExampleDatabase('/Users/andwhite/Projects/lipy-sso_trunk/lipy-sso/.hypothesis/examples')
rootdir: /Users/andwhite/Projects/lipy-sso_trunk/lipy-sso, inifile: setup.cfg
plugins: xdist-1.29.0, requests-mock-1.8.0, html-2.0.1, forked-0.2, lipy-config-base-21.0.8, hypothesis-4.40.0, metadata-1.8.0, cov-2.8.1, lipy-sso-2.1.0
collected 1 item                                                                                          

repro.py F                                                                                          [100%]

================================================ FAILURES =================================================
_____________________________________ test_url_fragment_without_query _____________________________________

    def test_url_fragment_without_query():
        url = Model(v='https://pydantic-docs.helpmanual.io/usage/types/#constrained-types').v
        assert url.query is None
>       assert url.fragment == 'constrainted-types'
E       AssertionError: assert None == 'constrainted-types'
E        +  where None = AnyUrl('https://pydantic-docs.helpmanual.io/usage/types/#constrained-types', scheme='https', host='pydantic-docs.helpmanual.io', tld='io', host_type='domain', path='/usage/types/#constrained-types').fragment

repro.py:11: AssertionError
============================================ 1 failed in 0.13s ============================================