Why companies prefer experience in Python over R in a data science interview?

Python is a language which is from the family of LISPS, and it the functional programming implementation of Python supports lambda calculus heavily. Also, the Machine Programming Language, also known as Caml is supported by Python itself.

Python is a pure OOP, in the sense that programmers don't really create the objects, instead, the objects are manipulated directly. This allows the extension of Python with C very easy. In fact, all the objects of Python are built in C, or to some extent Java, but C programming is heavily used.

Therefore, Python has not done it's tradeoff with speed and implementation. What we use in Python are wrappers of C functions ,which have been bundled as objects built in to the language. But, the PyObject takes care of the entire processing, therefore, programmers don't have to worry about the performance, and iwnstead can focus on the efficienty.

This makes Python very robust for Data Science application, because the objects can be extended for various machine learning tasks, such as predictions and classification. The machine learning has various algorithms which are sequential in nature, and Python's data structures such as lists and tuples are also sequences, and they make a perfect blend. Similarly, the dictionaries can be used to map weights and the values together, and neural network algorithm can be written.

R is good only till Data visualization, where in Python is in it's growing phase with all the ML & AI algorithms, Tensor flow, neural network frameworks etc also with hadoop Pyspark. Python has the clear dictionary of packages than R.