# Source code for networkx.classes.filters

```
"""Filter factories to hide or show sets of nodes and edges.
These filters return the function used when creating `SubGraph`.
"""
__all__ = [
"no_filter",
"hide_nodes",
"hide_edges",
"hide_multiedges",
"hide_diedges",
"hide_multidiedges",
"show_nodes",
"show_edges",
"show_multiedges",
"show_diedges",
"show_multidiedges",
]
[docs]
def no_filter(*items):
"""Returns a filter function that always evaluates to True."""
return True
[docs]
def hide_nodes(nodes):
"""Returns a filter function that hides specific nodes."""
nodes = set(nodes)
return lambda node: node not in nodes
[docs]
def hide_diedges(edges):
"""Returns a filter function that hides specific directed edges."""
edges = {(u, v) for u, v in edges}
return lambda u, v: (u, v) not in edges
[docs]
def hide_edges(edges):
"""Returns a filter function that hides specific undirected edges."""
alledges = set(edges) | {(v, u) for (u, v) in edges}
return lambda u, v: (u, v) not in alledges
[docs]
def hide_multidiedges(edges):
"""Returns a filter function that hides specific multi-directed edges."""
edges = {(u, v, k) for u, v, k in edges}
return lambda u, v, k: (u, v, k) not in edges
[docs]
def hide_multiedges(edges):
"""Returns a filter function that hides specific multi-undirected edges."""
alledges = set(edges) | {(v, u, k) for (u, v, k) in edges}
return lambda u, v, k: (u, v, k) not in alledges
# write show_nodes as a class to make SubGraph pickleable
[docs]
class show_nodes:
"""Filter class to show specific nodes."""
def __call__(self, node):
return node in self.nodes
[docs]
def show_diedges(edges):
"""Returns a filter function that shows specific directed edges."""
edges = {(u, v) for u, v in edges}
return lambda u, v: (u, v) in edges
[docs]
def show_edges(edges):
"""Returns a filter function that shows specific undirected edges."""
alledges = set(edges) | {(v, u) for (u, v) in edges}
return lambda u, v: (u, v) in alledges
[docs]
def show_multidiedges(edges):
"""Returns a filter function that shows specific multi-directed edges."""
edges = {(u, v, k) for u, v, k in edges}
return lambda u, v, k: (u, v, k) in edges
[docs]
def show_multiedges(edges):
"""Returns a filter function that shows specific multi-undirected edges."""
alledges = set(edges) | {(v, u, k) for (u, v, k) in edges}
return lambda u, v, k: (u, v, k) in alledges
```