def on_save(self, path=None):
"""
This is a hook that is called just before saving the file.
It can be used, for example, to update values in the metadata
that are based on the content of the data.
Override it in the subclass to make it do something, but don't
forget to "chain up" to the base class, since it does things
there, too.
Parameters
----------
path : str
The path to the file that we're about to save to.
"""
if isinstance(path, str):
self.meta.filename = os.path.basename(path)
current_date = Time(datetime.datetime.now())
current_date.format = 'isot'
self.meta.date = current_date.value
# Enforce model_type to be the actual type of model being saved.
self.meta.model_type = self._model_type
# Remove None nodes from the tree:
def _remove_none(node):
if node is None:
return RemoveNode
else:
return node
self._instance = treeutil.walk_and_modify(self._instance, _remove_none)
def test_walk_and_modify_shared_references():
target = {"foo": "bar"}
nested_in_dict = {"target": target}
nested_in_list = [target]
tree = {
"target": target,
"nested_in_dict": nested_in_dict,
"nested_in_list": nested_in_list
}
assert tree["target"] is tree["nested_in_dict"]["target"]
assert tree["target"] is tree["nested_in_list"][0]
def _callback(node):
if "foo" in node:
return {"foo": "baz"}
else:
return node
result = treeutil.walk_and_modify(tree, _callback)
assert result is not tree
assert result["target"] is not target
assert result["target"]["foo"] == "baz"
assert result["target"] is result["nested_in_dict"]["target"]
assert result["target"] is result["nested_in_list"][0]
def test_walk_and_modify_retain_none():
tree = {'foo': 42, 'bar': None}
def func(x):
if x == 42:
return None
return x
tree2 = treeutil.walk_and_modify(tree, func)
assert tree2['foo'] is None
assert tree2['bar'] is None
def test_walk_and_modify_remove_keys():
tree = {'foo': 42, 'bar': 43}
def func(x):
if x == 42:
return treeutil.RemoveNode
return x
tree2 = treeutil.walk_and_modify(tree, func)
assert 'foo' not in tree2
assert 'bar' in tree2
def test_walk_and_modify_remove_keys():
tree = {
'foo': 42,
'bar': 43
}
def func(x):
if x == 42:
return None
return x
tree2 = treeutil.walk_and_modify(tree, func)
assert 'foo' not in tree2
assert 'bar' in tree2
def _save_from_schema(hdulist, tree, schema):
def convert_datetimes(node, json_id):
if isinstance(node, datetime.datetime):
node = time.Time(node)
if isinstance(node, time.Time):
node = str(time.Time(node, format='iso'))
return node
tree = treeutil.walk_and_modify(tree, convert_datetimes)
validator = asdf_schema.get_validator(
schema, None, FITS_VALIDATORS, FITS_SCHEMA_URL_MAPPING)
validator.hdulist = hdulist
# TODO: Handle comment stack on per-hdu-basis
validator.comment_stack = []
# This actually kicks off the saving
validator.validate(tree, _schema=schema)
def _save_from_schema(hdulist, tree, schema):
def convert_datetimes(node, json_id):
if isinstance(node, datetime.datetime):
node = time.Time(node)
if isinstance(node, time.Time):
node = str(time.Time(node, format='iso'))
return node
tree = treeutil.walk_and_modify(tree, convert_datetimes)
validator = asdf_schema.get_validator(
schema, None, FITS_VALIDATORS, FITS_SCHEMA_URL_MAPPING)
validator.hdulist = hdulist
# TODO: Handle comment stack on per-hdu-basis
validator.comment_stack = []
# This actually kicks off the saving
validator.validate(tree, _schema=schema)
def remove_none_from_tree(tree):
"""
Remove None values from a tree. Both dictionary keys
and list indices with None values will be removed.
Parameters
----------
tree : object
The root node of the tree.
Returns
-------
object
Modified tree.
"""
def _remove_none(node):
if node is None:
return RemoveNode
else:
return node
return treeutil.walk_and_modify(tree, _remove_none)
from asdf.treeutil import walk_and_modify
tree = {
"a": {
"aa": 1,
"ab": 3
},
"b": 6,
"c": {
"ca": 5,
"cb": 7,
"cc": {
"cca": 3,
"ccb": 8,
"ccc": 9
},
"d": 2
},
}
def callback(node, json_id):
if isinstance(node, int) and node == 3:
print(f"json id: {json_id} / node: {node} -> -5")
return -5
print(f"json id: {json_id} / node: {node}")
return node
walk_and_modify(tree, callback, postorder=False)
