Looking for good source code either in C or C++ or Python to understand how a hash function is implemented and also how a hash table is implemented using it.
Very good material on how hash fn and hash table implementation works.

Thanks in advance.
When you want to learn, I suggest you look at the Java implementation of java.util.HashMap. It's clear code, well-documented and comparably short. Admitted, it's neither C, nor C++, nor Python, but you probably don't want to read the GNU libc++'s upcoming implementation of a hashtable, which above all consists of the complexity of the C++ standard template library.
To begin with, you should read the definition of the java.util.Map interface. Then you can jump directly into the details of the java.util.HashMap. And everything that's missing you will find in java.util.AbstractMap.
The implementation of a good hash function is independent of the programming language. The basic task of it is to map an arbitrarily large value set onto a small value set (usually some kind of integer type), so that the resulting values are evenly distributed.
Looking for production quality Hash table/ unordered map implementation to learn?