Which courses can 2nd year CSE students do during their summer vacation?

There are various courses that you can do in this summer vacation. Some of these are: Python C, C+, C# Ruby on Rails HTML and CSS Mogo db Java and JavaScript Out of these, I'll prefer you to first go for python and make it perfect.

There are following courses are available in different platform like:-Coursera, NPTEL, internal. Com, udemy. Com, edx. Org etc. These courses are- 1) Python and data structure. 2) Ruby on rail. 3) Data structure & algorithm. 4) Python & machine learning. 5) C/C+ complete etc.