sudo 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.
3 not fully installed or removed.
Need to get 0 B/462 kB of archives.
After this operation, 0 B of additional disk space will be used.
Do you want to continue [Y/n]? y
(Reading database ... 146909 files and directories currently installed.)
Preparing to replace software-center 4.0 (using .../software-center_4.0_all.deb) ...
  File "/usr/bin/pycentral", line 87
    raise ValueError, 'unknown version info %s' % vinfo
                    ^
SyntaxError: invalid syntax
dpkg: warning: subprocess old pre-removal script returned error exit status 1
dpkg - trying script from the new package instead ...
  File "/usr/bin/pycentral", line 87
    raise ValueError, 'unknown version info %s' % vinfo
                    ^
SyntaxError: invalid syntax
dpkg: error processing /var/cache/apt/archives/software-center_4.0_all.deb (--unpack):
 subprocess new pre-removal script returned error exit status 1
  File "/usr/bin/pycentral", line 87
    raise ValueError, 'unknown version info %s' % vinfo
                    ^
SyntaxError: invalid syntax
dpkg: error while cleaning up:
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 /var/cache/apt/archives/software-center_4.0_all.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)