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