braceexpand implements Bash-style brace expansion for Python,
as a single braceexpand() function returning an iterator over
the expansions of a pattern.  It supports comma-separated
alternatives ({a,b,c}), numeric and alphabetic sequences with
optional increments ({1..10}, {a..z}, {0..10..2}), zero
padding ({01..20}), nesting, and backslash escaping of the
special characters.
