I am new to Python and looking to build rest full web services using python. Due to some dependency, Could not use any other scripting language.
Anyone can suggest if Python has any api-only kind of framework or if any other lightweight framework for rest APIs in Python.
Thanks,
Pooja
as of SEP18, also have a look on Quart, APIstar
as of MAR19, add fastAPI, looks very promising
nota: 
Bottle is lighter (& faster) than Flask, but with less bells & whistles
Falcon is fast !
fastAPI is fast as well !
also, as Bottle/Flask are more general frameworks (they have templating features for instance, not API related), frameworks such as Falcon or fastAPI are really designed to serve as APIs framework.
Which python framework will be suitable to rest api only