gensim.interfaces.TransformedCorpus - How use?

I was facing the same problem. This code will solve your problem:

new_topics = new_lda[corpus]

for topic in new_topics:

      print(topic)

This will give you a list of tuples of form (topic number, probability)

From the 'Topics_and_Transformation.ipynb' tutorial prepared by the RaRe Technologies people:

Converting the entire corpus at the time of calling corpus_transformed = model[corpus] would mean storing the result in main memory, and that contradicts gensim’s objective of memory-independence.

If you will be iterating over the transformed corpus_transformed multiple times, and the transformation is costly, serialize the resulting corpus to disk first and continue using that.

Hope it helps.