Recursive chmod fails
The issue is that to be able to write to a file you need to be the owner for u permissions or be part of the group for g.

Note as a user you are not root so if owned by root the u permission does not matter. As you are using sudo I assume you are in the admin group (this is not necessarily the case but if anyone  alters this I would expect they fully understand these permissions). These files are owned by admin so the permission that matters is the g one.

Thus the chomd you need is

sudo chmod -v -R g+w some-folder/


There are alternatives


As this is where python is installed you should be using pip, easy_install and setuptools to do these updates which will require sudo. Another way is to use virtualenv and so install will be done to your own directories  
You can change the owner
sudo chown -R user some-folder/