def reverse_dots(name):
    """Reverse dotted IP addresses or domain names.

    Example:
    >>> reverse_dots('192.168.0.145')
    '145.0.168.192'

    >>> reverse_dots('email.example.com')
    'com.example.email'
    """
    a = name.split('.')
    a.reverse()
    return '.'.join(a)
Reverse dotted IP addresses or domain names.

    Example:
    >>> reverse_dots('192.168.0.145')
    '145.0.168.192'

    >>> reverse_dots('email.example.com')
    'com.example.email'
    
python/spf.py