Guide To: Learning Python Decorators is a complete guide to the theory and implementation of decorators. Decorators are pretty common in Python. While not strictly necessary, they can reduce code size while enabling control of function input, invocation and output. Many explanations of decorators are brief and leave the reader somewhat confused. This book is an attempt to remedy that. It is based off of popular tutorials given at PyCon and Python user groups. Without fail, attendees mention that “decorators now make sense”. Not only do they understand them, but they can write them as well.