def test__slice_object():
s = _slice(1, 10, 2)
assert str(s) == '1:10:2'
assert hash(s)
assert _slice(1, 10, 2) == _slice(1, 10, 2)
def from_tree(expr, namespace=None):
""" Convert core data structures to Blaze expression
Core data structure representations created by ``to_tree`` are converted
back into Blaze expressions.
Parameters
----------
expr: dict
Examples
--------
>>> t = symbol('t', 'var * {x: int32, y: int32}')
>>> tree = to_tree(t)
>>> tree # doctest: +SKIP
{'op': 'Symbol',
'args': ['t', 'var * { x : int32, y : int32 }', False]}
>>> from_tree(tree)
t
>>> tree = to_tree(t.x.sum())
>>> tree # doctest: +SKIP
{'op': 'sum',
'args': [
{'op': 'Field',
'args': [
{
'op': 'Symbol'
'args': ['t', 'var * { x : int32, y : int32 }', False]
}
'x']
}]
}
>>> from_tree(tree)
sum(t.x)
Simplify expresion using explicit ``names`` dictionary. In the example
below we replace the ``Symbol`` node with the string ``'t'``.
>>> tree = to_tree(t.x, names={t: 't'})
>>> tree # doctest: +SKIP
{'op': 'Field', 'args': ['t', 'x']}
>>> from_tree(tree, namespace={'t': t})
t.x
See Also
--------
blaze.server.server.to_tree
"""
if isinstance(expr, dict):
op, args = expr['op'], expr['args']
if 'slice' == op:
return expr_utils._slice(
*[from_tree(arg, namespace) for arg in args])
if hasattr(blaze.expr, op):
cls = getattr(blaze.expr, op)
else:
cls = expression_from_name(op)
if 'Symbol' in op:
children = [from_tree(arg) for arg in args]
else:
children = [from_tree(arg, namespace) for arg in args]
return cls(*children)
elif isinstance(expr, list):
return tuple(from_tree(arg, namespace) for arg in expr)
if namespace and expr in namespace:
return namespace[expr]
else:
return expr
def from_tree(expr, namespace=None):
""" Convert core data structures to Blaze expression
Core data structure representations created by ``to_tree`` are converted
back into Blaze expressions.
Parameters
----------
expr : dict
Examples
--------
>>> t = symbol('t', 'var * {x: int32, y: int32}')
>>> tree = to_tree(t)
>>> tree # doctest: +SKIP
{'op': 'Symbol',
'args': ['t', 'var * { x : int32, y : int32 }', False]}
>>> from_tree(tree)
t
>>> tree = to_tree(t.x.sum())
>>> tree # doctest: +SKIP
{'op': 'sum',
'args': [
{'op': 'Field',
'args': [
{
'op': 'Symbol'
'args': ['t', 'var * { x : int32, y : int32 }', False]
}
'x']
}]
}
>>> from_tree(tree)
sum(t.x)
Simplify expresion using explicit ``names`` dictionary. In the example
below we replace the ``Symbol`` node with the string ``'t'``.
>>> tree = to_tree(t.x, names={t: 't'})
>>> tree # doctest: +SKIP
{'op': 'Field', 'args': ['t', 'x']}
>>> from_tree(tree, namespace={'t': t})
t.x
See Also
--------
to_tree
"""
if isinstance(expr, dict):
op, args = expr['op'], expr['args']
if 'slice' == op:
return expr_utils._slice(*[from_tree(arg, namespace)
for arg in args])
if hasattr(blaze.expr, op):
cls = getattr(blaze.expr, op)
else:
cls = expression_from_name(op)
if 'Symbol' in op:
children = [from_tree(arg) for arg in args]
else:
children = [from_tree(arg, namespace) for arg in args]
return cls(*children)
elif isinstance(expr, list):
return tuple(from_tree(arg, namespace) for arg in expr)
if namespace and expr in namespace:
return namespace[expr]
else:
return expr