Answer 1

If you don't need argument validation, it's a one-liner function:

def dateConv(date):
return "/".join(a[2:].split('-')[::-1])

a = "2016-1-25"
print(dateConv(a))

>>>
25/1/16

https://code.sololearn.com/cqny043e5OjS/?ref=app

Also, check out my Date Converter I to get the idea:
https://code.sololearn.com/crgVNxIU9Cdy/?ref=app