Google translate as Python module & command line tool. No key, no authentication whatsoever. The default target language is Simplified Chinese.
利用google translate实现的命令行工具（translate），也可以当做Python模块用在你的代码中。
pip install translate
Or, you can download the source and
python setup.py install
Add sudo in the beginning if you met problem.
In your command-line:
translate "This is a pen."
Or
translate -f zh -t ja 我是谁？
from translate import Translator
translator= Translator(to_lang="zh")
translation = translator.translate("This is a pen.")
The result is in translation, and it’s usually a unicode string.