debian 升级时出错

apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
1 not fully installed or removed.
After this operation, 0B of additional disk space will be used.
Do you want to continue [Y/n]? y
Setting up python-elementtree (1.2.6-13) ...
Usage: update-python-modules [-v] [-c] package_directory [...]
update-python-modules [-v] [-c] package.dirs [...]
update-python-modules [-v] [-a|-f|-p]

update-python-modules: error: /usr/share/python-support/python-elementtree.public is not a directory
dpkg: error processing python-elementtree (--configure):
subprocess post-installation script returned error exit status 2
Errors were encountered while processing:
python-elementtree
E: Sub-process /usr/bin/dpkg returned an error code (1)