What is the simplest way to swap each pair of adjoining chars in a string with Python?

Question

I want to swap each pair of characters in a string. \'2143\' becomes \'1234\', \'badcfe\' becomes \'abcdef\'.

How

Answer 1

#Think about how index works with string in Python,
>>> a = "123456"
>>> a[::-1]
'654321'