hey guys, is python is version oriented language because in most of the ide they are python 2.x and 3.x was available

can u tell why 2 versions of python available.....???

if I learn python 2.x I can not able to code in 3.x
other languages like c,c++, java are not like that hope version is different available but not split like python ...

so if I learn py3.x now in future sure will be 4.x then what i learnt in 3.x will go in vain?