Custom sort in Python3 ref: http://qiita.com/giwa/items/afd1476c5211e28361ba

file0.txt

>>> def compare(a, b):
...     """Comparison that ignores the first letter"""
...     return cmp(a[1:], b[1:])
>>> names = ['Adam', 'Donald', 'John']
>>> names.sort(cmp=compare)
>>> names
['Adam', 'John', 'Donald']

file1.txt

>>> names = ['Adam', 'Donald', 'John']
>>> names.sort(key=lambda x: x[1:])
>>> names
['Adam', 'John', 'Donald']

file2.txt

>>> l = [('betty', 1), ('a', 1), ('butter', 2)]
>>> def custom_key(x):
...     return -x[1], x[0]
...
>>> l.sort(key=custom_key)
>>> l
[('butter', 2), ('a', 1), ('betty', 1)]