<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def upload():
 """Upload source to PyPI using twine."""

    try:
        o = check_output(['twine', 'upload'] + glob('dist/*'))
    except CalledProcessError:
        call(['twine', 'upload'] + glob('dist/*'))
        raise
    print(o.decode('utf-8'))