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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_rev_options(url, rev):
 """Return revision options. from pip pip.vcs.subversion. """

    if rev:
        rev_options = ['-r', rev]
    else:
        rev_options = []

    r = urlparse.urlsplit(url)
    if hasattr(r, 'username'):
        # >= Python-2.5
        username, password = r.username, r.password
    else:
        netloc = r[1]
        if '@' in netloc:
            auth = netloc.split('@')[0]
            if ':' in auth:
                username, password = auth.split(':', 1)
            else:
                username, password = auth, None
        else:
            username, password = None, None

    if username:
        rev_options += ['--username', username]
    if password:
        rev_options += ['--password', password]
    return rev_options