Some programming languages have stated capitalization preferences that are easy to find online, and have a set of rules more complex than one would think. For example, Python is spelled with a capital P when speaking about the language itself (such as on a resume), BUT you write python in your IDE. Additionally, some language names have special forms in special cases. For example, we can debate whether or not this code is pythonic.
Also, one of the comments on the question above makes a very good point that I will take a step further in giving you some job-seeking advice: If you don't know the proper capitalization of the programming language you are thinking about adding to your resume, it does not belong on your resume.