def flatten(tree, leaves=()):
''' Flatten a tree, that is, recursively concatenate nested sequences.
>>> flatten([1, [[2, 3], 4, 5], [[[[6]]]]])
[1, 2, 3, 4, 5, 6]
>>> mixed = [1, [[2], 3], (4, 5), [(6,)], 'abc']
>>> flatten(mixed)
[1, 2, 3, 4, 5, 6, 'a', 'b', 'c']
>>> flatten(mixed, leaves=(str,))
[1, 2, 3, 4, 5, 6, 'abc']
>>> flatten(mixed, leaves=(str, tuple))
[1, 2, 3, (4, 5), (6,), 'abc']
>>> flatten([])
[]
>>> flatten(1)
[1]
'''
# Pass leaf types around, avoiding infinite regress on strings
_is_fork = partial(is_fork, leaves=leaves)
if isinstance(tree, basestring):
leaves += (basestring, )
_flatten = partial(flatten, leaves=leaves)
if not _is_fork(tree):
return [tree]
else:
return concat(_flatten(n) for n in tree)
def flatten(tree, leaves=()):
''' Flatten a tree, that is, recursively concatenate nested sequences.
>>> flatten([1, [[2, 3], 4, 5], [[[[6]]]]])
[1, 2, 3, 4, 5, 6]
>>> mixed = [1, [[2], 3], (4, 5), [(6,)], 'abc']
>>> flatten(mixed)
[1, 2, 3, 4, 5, 6, 'a', 'b', 'c']
>>> flatten(mixed, leaves=(str,))
[1, 2, 3, 4, 5, 6, 'abc']
>>> flatten(mixed, leaves=(str, tuple))
[1, 2, 3, (4, 5), (6,), 'abc']
>>> flatten([])
[]
>>> flatten(1)
[1]
'''
# Pass leaf types around, avoiding infinite regress on strings
_is_fork = partial(is_fork, leaves=leaves)
if isinstance(tree, basestring):
leaves += (basestring,)
_flatten = partial(flatten, leaves=leaves)
if not _is_fork(tree):
return [tree]
else:
return concat(_flatten(n) for n in tree)
def _get_sub_context_names ( self ):
return concat( self._sub_contexts.values() )
