On future tickets please use WikiFormatting when quoting from terminal output or log files for better readibility, copy the port maintainers
port info --maintainer py27-pep8 py27-pep8-157
and fill in the Port field of the ticket. Thanks.
Note that, according to your terminal output, the conflict is between py27-pep8 and py27-pep8-157. Ports that have a dependency on py-pep8 currently depend on py-pep8-157 due to a regression in the 1.6.x series of py-pep8 that, in particular, effected py-flake8. Recently released py-pep8 1.7.0 claims to have fixed this issue so upgrading to this version as well as latest py-flake8 1.5.2 should allow this conflict to be removed.
In the meantime, if you really don't need to use py-pep8 1.6.x, just deactivate this port. No other ports currently depend on it.
sudo port deactivate py27-pep8