Ideally, you should have a basic knowledge of how Python code is written and structured. If you are not familiar with Python or are not clear how programming languages work in general, then please take at look at a book on Python. A book dealing with Python from a data science perspective would be ideal for you.
If you already have a basic idea of NLP and machine learning in general, this book should be easy for you to grasp. If you are starting out in NLP, that should not be too much of an issue if you are willing to dive deep into the mathematics covered. I have taken care to explain the mathematical concepts covered in this book, but if this too seems too difficult, please write to us and let us know.
A willingness on the part of the reader to dive deep and try out all the code is assumed.