Translate 漢字 to ㄅㄆㄇㄈ, based on lxneng/xpinyin.
pip install bopomofo
>>> from bopomofo import to_bopomofo
>>> to_bopomofo(u'注音')
'ㄓㄨˋ ㄧㄣ'
>>> to_bopomofo(u'注音', tones=False)
'ㄓㄨ ㄧㄣ'
>>> to_bopomofo(u'注音', u'、')
'ㄓㄨˋ、ㄧㄣ'
>>> bopomofo.to_bopomofo(u'注音', first_tone_symbol=True)
'ㄓㄨˋ ㄧㄣˉ'