capybara/virtualenv/lib/python2.7/site-packages/pip/_vendor/pkg_resources/__init__.py
def yield_lines(strs):
    """Yield non-empty/non-comment lines of a string or sequence"""
    if isinstance(strs, string_types):
        for s in strs.splitlines():
            s = s.strip()
            # skip blank lines/comments
            if s and not s.startswith('#'):
                yield s
    else:
        for ss in strs:
            for s in yield_lines(ss):
                yield s
def yield_lines(strs):
    """Yield non-empty/non-comment lines of a string or sequence"""
    if isinstance(strs, string_types):
        for s in strs.splitlines():
            s = s.strip()
            # skip blank lines/comments
            if s and not s.startswith('#'):
                yield s
    else:
        for ss in strs:
            for s in yield_lines(ss):
                yield s
Yield non-empty/non-comment lines of a string or sequence