python url解析path_python 将相对url路径解析为其绝对路径

def urljoin(base, url, allow_fragments=True):

"""Join a base URL and a possibly relative URL to form an absolute

interpretation of the latter."""

if not base:

return url

if not url:

return base

base, url, _coerce_result = _coerce_args(base, url)

bscheme, bnetloc, bpath, bparams, bquery, bfragment = \

urlparse(base, '', allow_fragments)

scheme, netloc, path, params, query, fragment = \

urlparse(url, bscheme, allow_fragments)

if scheme != bscheme or scheme not in uses_relative:

return _coerce_result(url)

if scheme in uses_netloc:

if netloc:

return _coerce_result(urlunparse((scheme, netloc, path,

params, query, fragment)))

netloc = bnetloc

if not path and not params:

path = bpath

params = bparams

if not query:

query = bquery

return _coerce_result(urlunparse((scheme, netloc, path,

params, query, fragment)))

base_parts = bpath.split('/')

if base_parts[-1] != '':

# the last item is not a directory, so will not be taken into account

# in resolving the relative path

del base_parts[-1]

# for rfc3986, ignore all base path should the first character be root.

if path[:1] == '/':

segments = path.split('/')

else:

segments = base_parts + path.split('/')

# filter out elements that would cause redundant slashes on re-joining

# the resolved_path

segments[1:-1] = filter(None, segments[1:-1])

resolved_path = []

for seg in segments:

if seg == '..':

try:

resolved_path.pop()

except IndexError:

# ignore any .. segments that would otherwise cause an IndexError

# when popped from resolved_path if resolving for rfc3986

pass

elif seg == '.':

continue

else:

resolved_path.append(seg)

if segments[-1] in ('.', '..'):

# do some post-processing here. if the last segment was a relative dir,

# then we need to append the trailing '/'

resolved_path.append('')

return _coerce_result(urlunparse((scheme, netloc, '/'.join(

resolved_path) or '/', params, query, fragment)))