test = "hello,how are you?I am fine,thank you. And you?"
print [t for x in test.split(",")
for y in x.split(".")
for z in y.split("?")
for t in z.split()]
dGVzdCA9ICJoZWxsbyxob3cgYXJlIHlvdT9JIGFtIGZpbmUsdGhhbmsgeW91LiBBbmQgeW91PyIKCnByaW50IFt0IGZvciB4IGluIHRlc3Quc3BsaXQoIiwiKQogICAgICAgICBmb3IgeSBpbiB4LnNwbGl0KCIuIikKICAgICAgICAgZm9yIHogaW4geS5zcGxpdCgiPyIpCiAgICAgICAgIGZvciB0IGluIHouc3BsaXQoKV0=
['hello', 'how', 'are', 'you', 'I', 'am', 'fine', 'thank', 'you', 'And', 'you']