使用python-pptx替换ppt各个方面的特定文本

I am new with python-pptx. But I am familiar with its basic working. I have searched a lot but I could not find a way to change a particular text by another text in all slides. That text may be in any text_frame of a slide. like all slides in a ppt have 'java' keyword, I want to change it by 'python' using python pptx in slides. I am new with python-pptx. But I am familiar wi