I need to do some deep learning work in python, mainly image processing based work. Do Python have any standard library or API which is works works like deeplearning4j?
You can try scikit-image module (http://scikit-image.org/) for it. You can also try deep learning python module, Caffe (http://caffe.berkeleyvision.org/), which is mainly based on scikit-image.
Here another example for Deep learning using scikit-learn :
As an extension of the previous answer, I have used Keras and Lasgne. I have also tried out Blocks and Pylearn2. All are very good solutions. You can have a look at this blog post which is well written: