url拼接for py3
from urllib.parse import urljoin
from urllib.parse import urlparse
from urllib.parse import urlunparse
from posixpath import normpath
def myjoin(base, url):
url1 = urljoin(base, url)
arr = urlparse(url1)
path = normpath(arr[2])
return urlunparse((arr.scheme, arr.netloc, path, arr.params, arr.query, arr.fragment))