Is there a cleaner way to modify some parts of a URL in Python 2?
For example
http://foo/bar -> http://foo/yah
At present, I'm doing this:
import urlparse
url = 'http://foo/bar'
# Modify path component of URL from 'bar' to 'yah'
# Use nasty convert-to-list hack due to urlparse.ParseResult being immutable
parts = list(urlparse.urlparse(url))
parts[2] = 'yah'
url = urlparse.urlunparse(parts)
Is there a cleaner solution?
Unfortunately, the documentation is out of date; the results produced by urlparse.urlparse() (and urlparse.urlsplit()) use a collections.namedtuple()-produced class as a base.
Don't turn this namedtuple into a list, but make use of the utility method provided for just this task:
parts = urlparse.urlparse(url)
parts = parts._replace(path='yah')
url = parts.geturl()
The namedtuple._replace() method lets you create a new copy with specific elements replaced. The ParseResult.geturl() method then re-joins the parts into a url for you.
Demo:
>>> import urlparse
>>> url = 'http://foo/bar'
>>> parts = urlparse.urlparse(url)
>>> parts = parts._replace(path='yah')
>>> parts.geturl()
'http://foo/yah'
mgilson filed a bug report (with patch) to address the documentation issue.
urlparse.ParseResult by the subclass returned by namedtuple. I think that this should be pointed out in the 2.7 docs, because without knowing that, you have no way of knowing that _replace actually is part of the public API for this class...BaseResult in the docs which doesn't appear in the source at all ... (sorry about the digression ... It's late ... +1 anyway)
namedtuple was used.
I guess the proper way to do it is this way.
As using _replace private methods or variables is not suggested.
from urlparse import urlparse, urlunparse
res = urlparse('http://www.goog.com:80/this/is/path/;param=paramval?q=val&foo=bar#hash')
l_res = list(res)
# this willhave ['http', 'www.goog.com:80', '/this/is/path/', 'param=paramval', 'q=val&foo=bar', 'hash']
l_res[2] = '/new/path'
urlunparse(l_res)
# outputs 'http://www.goog.com:80/new/path;param=paramval?q=val&foo=bar#hash'
