tests/sitecustomize.py

match: move matchers from sparse into core

The sparse extension contains some matcher types that are
generic and can exist in core.

As part of the move, the classes now inherit from basematcher.
always(), files(), and isexact() have been dropped because
they match the default implementations in basematcher.

from __future__ import absolute_import
import os

if os.environ.get('COVERAGE_PROCESS_START'):
    try:
        import coverage
        import uuid

        covpath = os.path.join(os.environ['COVERAGE_DIR'],
                               'cov.%s' % uuid.uuid1())
        cov = coverage.coverage(data_file=covpath, auto_data=True)
        cov._warn_no_data = False
        cov._warn_unimported_source = False
        cov.start()
    except ImportError:
        pass