Source code for networkx.classes.coreviews

"""Views of core data structures such as nested Mappings (e.g. dict-of-dicts).
These ``Views`` often restrict element access, with either the entire view or
layers of nested mappings being read-only.
"""

from collections.abc import Mapping

__all__ = [
    "AtlasView",
    "AdjacencyView",
    "MultiAdjacencyView",
    "UnionAtlas",
    "UnionAdjacency",
    "UnionMultiInner",
    "UnionMultiAdjacency",
    "FilterAtlas",
    "FilterAdjacency",
    "FilterMultiInner",
    "FilterMultiAdjacency",
]


[docs] class AtlasView(Mapping): """An AtlasView is a Read-only Mapping of Mappings. It is a View into a dict-of-dict data structure. The inner level of dict is read-write. But the outer level is read-only. See Also ======== AdjacencyView: View into dict-of-dict-of-dict MultiAdjacencyView: View into dict-of-dict-of-dict-of-dict """ __slots__ = ("_atlas",) def __getstate__(self): return {"_atlas": self._atlas} def __setstate__(self, state): self._atlas = state["_atlas"]
[docs] def __init__(self, d): self._atlas = d
def __len__(self): return len(self._atlas) def __iter__(self): return iter(self._atlas) def __getitem__(self, key): return self._atlas[key]
[docs] def copy(self): return {n: self[n].copy() for n in self._atlas}
def __str__(self): return str(self._atlas) # {nbr: self[nbr] for nbr in self}) def __repr__(self): return f"{self.__class__.__name__}({self._atlas!r})"
[docs] class AdjacencyView(AtlasView): """An AdjacencyView is a Read-only Map of Maps of Maps. It is a View into a dict-of-dict-of-dict data structure. The inner level of dict is read-write. But the outer levels are read-only. See Also ======== AtlasView: View into dict-of-dict MultiAdjacencyView: View into dict-of-dict-of-dict-of-dict """ __slots__ = () # Still uses AtlasView slots names _atlas def __getitem__(self, name): return AtlasView(self._atlas[name])
[docs] def copy(self): return {n: self[n].copy() for n in self._atlas}
[docs] class MultiAdjacencyView(AdjacencyView): """An MultiAdjacencyView is a Read-only Map of Maps of Maps of Maps. It is a View into a dict-of-dict-of-dict-of-dict data structure. The inner level of dict is read-write. But the outer levels are read-only. See Also ======== AtlasView: View into dict-of-dict AdjacencyView: View into dict-of-dict-of-dict """ __slots__ = () # Still uses AtlasView slots names _atlas def __getitem__(self, name): return AdjacencyView(self._atlas[name])
[docs] def copy(self): return {n: self[n].copy() for n in self._atlas}
[docs] class UnionAtlas(Mapping): """A read-only union of two atlases (dict-of-dict). The two dict-of-dicts represent the inner dict of an Adjacency: `G.succ[node]` and `G.pred[node]`. The inner level of dict of both hold attribute key:value pairs and is read-write. But the outer level is read-only. See Also ======== UnionAdjacency: View into dict-of-dict-of-dict UnionMultiAdjacency: View into dict-of-dict-of-dict-of-dict """ __slots__ = ("_succ", "_pred") def __getstate__(self): return {"_succ": self._succ, "_pred": self._pred} def __setstate__(self, state): self._succ = state["_succ"] self._pred = state["_pred"]
[docs] def __init__(self, succ, pred): self._succ = succ self._pred = pred
def __len__(self): return len(self._succ.keys() | self._pred.keys()) def __iter__(self): return iter(set(self._succ.keys()) | set(self._pred.keys())) def __getitem__(self, key): try: return self._succ[key] except KeyError: return self._pred[key]
[docs] def copy(self): result = {nbr: dd.copy() for nbr, dd in self._succ.items()} for nbr, dd in self._pred.items(): if nbr in result: result[nbr].update(dd) else: result[nbr] = dd.copy() return result
def __str__(self): return str({nbr: self[nbr] for nbr in self}) def __repr__(self): return f"{self.__class__.__name__}({self._succ!r}, {self._pred!r})"
[docs] class UnionAdjacency(Mapping): """A read-only union of dict Adjacencies as a Map of Maps of Maps. The two input dict-of-dict-of-dicts represent the union of `G.succ` and `G.pred`. Return values are UnionAtlas The inner level of dict is read-write. But the middle and outer levels are read-only. succ : a dict-of-dict-of-dict {node: nbrdict} pred : a dict-of-dict-of-dict {node: nbrdict} The keys for the two dicts should be the same See Also ======== UnionAtlas: View into dict-of-dict UnionMultiAdjacency: View into dict-of-dict-of-dict-of-dict """ __slots__ = ("_succ", "_pred") def __getstate__(self): return {"_succ": self._succ, "_pred": self._pred} def __setstate__(self, state): self._succ = state["_succ"] self._pred = state["_pred"]
[docs] def __init__(self, succ, pred): # keys must be the same for two input dicts assert len(set(succ.keys()) ^ set(pred.keys())) == 0 self._succ = succ self._pred = pred
def __len__(self): return len(self._succ) # length of each dict should be the same def __iter__(self): return iter(self._succ) def __getitem__(self, nbr): return UnionAtlas(self._succ[nbr], self._pred[nbr])
[docs] def copy(self): return {n: self[n].copy() for n in self._succ}
def __str__(self): return str({nbr: self[nbr] for nbr in self}) def __repr__(self): return f"{self.__class__.__name__}({self._succ!r}, {self._pred!r})"
[docs] class UnionMultiInner(UnionAtlas): """A read-only union of two inner dicts of MultiAdjacencies. The two input dict-of-dict-of-dicts represent the union of `G.succ[node]` and `G.pred[node]` for MultiDiGraphs. Return values are UnionAtlas. The inner level of dict is read-write. But the outer levels are read-only. See Also ======== UnionAtlas: View into dict-of-dict UnionAdjacency: View into dict-of-dict-of-dict UnionMultiAdjacency: View into dict-of-dict-of-dict-of-dict """ __slots__ = () # Still uses UnionAtlas slots names _succ, _pred def __getitem__(self, node): in_succ = node in self._succ in_pred = node in self._pred if in_succ: if in_pred: return UnionAtlas(self._succ[node], self._pred[node]) return UnionAtlas(self._succ[node], {}) return UnionAtlas({}, self._pred[node])
[docs] def copy(self): nodes = set(self._succ.keys()) | set(self._pred.keys()) return {n: self[n].copy() for n in nodes}
[docs] class UnionMultiAdjacency(UnionAdjacency): """A read-only union of two dict MultiAdjacencies. The two input dict-of-dict-of-dict-of-dicts represent the union of `G.succ` and `G.pred` for MultiDiGraphs. Return values are UnionAdjacency. The inner level of dict is read-write. But the outer levels are read-only. See Also ======== UnionAtlas: View into dict-of-dict UnionMultiInner: View into dict-of-dict-of-dict """ __slots__ = () # Still uses UnionAdjacency slots names _succ, _pred def __getitem__(self, node): return UnionMultiInner(self._succ[node], self._pred[node])
[docs] class FilterAtlas(Mapping): # nodedict, nbrdict, keydict """A read-only Mapping of Mappings with filtering criteria for nodes. It is a view into a dict-of-dict data structure, and it selects only nodes that meet the criteria defined by ``NODE_OK``. See Also ======== FilterAdjacency FilterMultiInner FilterMultiAdjacency """
[docs] def __init__(self, d, NODE_OK): self._atlas = d self.NODE_OK = NODE_OK
def __len__(self): # check whether NODE_OK stores the number of nodes as `length` # or the nodes themselves as a set `nodes`. If not, count the nodes. if hasattr(self.NODE_OK, "length"): return self.NODE_OK.length if hasattr(self.NODE_OK, "nodes"): return len(self.NODE_OK.nodes & self._atlas.keys()) return sum(1 for n in self._atlas if self.NODE_OK(n)) def __iter__(self): try: # check that NODE_OK has attr 'nodes' node_ok_shorter = 2 * len(self.NODE_OK.nodes) < len(self._atlas) except AttributeError: node_ok_shorter = False if node_ok_shorter: return (n for n in self.NODE_OK.nodes if n in self._atlas) return (n for n in self._atlas if self.NODE_OK(n)) def __getitem__(self, key): if key in self._atlas and self.NODE_OK(key): return self._atlas[key] raise KeyError(f"Key {key} not found") def __str__(self): return str({nbr: self[nbr] for nbr in self}) def __repr__(self): return f"{self.__class__.__name__}({self._atlas!r}, {self.NODE_OK!r})"
[docs] class FilterAdjacency(Mapping): # edgedict """A read-only Mapping of Mappings with filtering criteria for nodes and edges. It is a view into a dict-of-dict-of-dict data structure, and it selects nodes and edges that satisfy specific criteria defined by ``NODE_OK`` and ``EDGE_OK``, respectively. See Also ======== FilterAtlas FilterMultiInner FilterMultiAdjacency """
[docs] def __init__(self, d, NODE_OK, EDGE_OK): self._atlas = d self.NODE_OK = NODE_OK self.EDGE_OK = EDGE_OK
def __len__(self): # check whether NODE_OK stores the number of nodes as `length` # or the nodes themselves as a set `nodes`. If not, count the nodes. if hasattr(self.NODE_OK, "length"): return self.NODE_OK.length if hasattr(self.NODE_OK, "nodes"): return len(self.NODE_OK.nodes & self._atlas.keys()) return sum(1 for n in self._atlas if self.NODE_OK(n)) def __iter__(self): try: # check that NODE_OK has attr 'nodes' node_ok_shorter = 2 * len(self.NODE_OK.nodes) < len(self._atlas) except AttributeError: node_ok_shorter = False if node_ok_shorter: return (n for n in self.NODE_OK.nodes if n in self._atlas) return (n for n in self._atlas if self.NODE_OK(n)) def __getitem__(self, node): if node in self._atlas and self.NODE_OK(node): def new_node_ok(nbr): return self.NODE_OK(nbr) and self.EDGE_OK(node, nbr) return FilterAtlas(self._atlas[node], new_node_ok) raise KeyError(f"Key {node} not found") def __str__(self): return str({nbr: self[nbr] for nbr in self}) def __repr__(self): name = self.__class__.__name__ return f"{name}({self._atlas!r}, {self.NODE_OK!r}, {self.EDGE_OK!r})"
[docs] class FilterMultiInner(FilterAdjacency): # muliedge_seconddict """A read-only Mapping of Mappings with filtering criteria for nodes and edges. It is a view into a dict-of-dict-of-dict-of-dict data structure, and it selects nodes and edges that meet specific criteria defined by ``NODE_OK`` and ``EDGE_OK``. See Also ======== FilterAtlas FilterAdjacency FilterMultiAdjacency """ def __iter__(self): try: # check that NODE_OK has attr 'nodes' node_ok_shorter = 2 * len(self.NODE_OK.nodes) < len(self._atlas) except AttributeError: node_ok_shorter = False if node_ok_shorter: my_nodes = (n for n in self.NODE_OK.nodes if n in self._atlas) else: my_nodes = (n for n in self._atlas if self.NODE_OK(n)) for n in my_nodes: some_keys_ok = False for key in self._atlas[n]: if self.EDGE_OK(n, key): some_keys_ok = True break if some_keys_ok is True: yield n def __getitem__(self, nbr): if nbr in self._atlas and self.NODE_OK(nbr): def new_node_ok(key): return self.EDGE_OK(nbr, key) return FilterAtlas(self._atlas[nbr], new_node_ok) raise KeyError(f"Key {nbr} not found")
[docs] class FilterMultiAdjacency(FilterAdjacency): # multiedgedict """A read-only Mapping of Mappings with filtering criteria for nodes and edges. It is a view into a dict-of-dict-of-dict-of-dict data structure, and it selects nodes and edges that satisfy specific criteria defined by ``NODE_OK`` and ``EDGE_OK``, respectively. See Also ======== FilterAtlas FilterAdjacency FilterMultiInner """ def __getitem__(self, node): if node in self._atlas and self.NODE_OK(node): def edge_ok(nbr, key): return self.NODE_OK(nbr) and self.EDGE_OK(node, nbr, key) return FilterMultiInner(self._atlas[node], self.NODE_OK, edge_ok) raise KeyError(f"Key {node} not found")