GitLab

I'm using graph_tool-2.43. Consider the following code. The giter_all_edges is a wrapper that needs to manually check the reversed status and adjust the order of edges. I assume that this is a bug, since giter_edges doesn't have to do this.

from graph_tool import (Graph, Vertex, Edge, GraphView)

def giter_all_edges(g:Graph,v,eprops=[]):                                        
  for xs in g.iter_all_edges(v,eprops):                                          
    yield tuple([xs[1],xs[0]]+xs[2:]) if g.is_reversed() else xs # <-- Need to manually reverse nodes (!!!)

def giter_edges(g:Graph,eprops=[]):                                              
  for xs in g.iter_edges(eprops):                                                
    yield xs                                                                     
             
# Create a 2-node graph with an edge
g=Graph(directed=True)                                                         
v1=g.add_vertex()                                                              
v2=g.add_vertex()                                                              
e1=g.edge(v1,v2,add_missing=True)                                              
eprop=g.new_ep('int64_t')                                                      
edges={}                                                                       
for s,t in g.iter_edges([]):                                                   
  eprop[g.edge(s,t)]=111                                                       
  edges[s]=t                                                                   
assert len(edges)==1              

# Make sure that iterators work correctly                                             
for s,t,e in giter_all_edges(g,v1,[eprop]):                                    
  assert eprop[g.edge(s,t)]==111                                               
  assert edges[s]==t                                                           
for s,t,e in giter_edges(g,[eprop]):                                           
  assert eprop[g.edge(s,t)]==111                                               
  assert edges[s]==t                     

# Reverse the graph                                      
g.set_reversed(True) 

# Oh no, without the wrapper this would fail                                                          
for s,t,e in giter_all_edges(g,v1,[eprop]):                                    
  assert eprop[g.edge(s,t)]==111                                               
  assert edges[t]==s                    
# .. and this would not                                       
for s,t,e in giter_edges(g,[eprop]):                                           
  assert eprop[g.edge(s,t)]==111                                               
  assert edges[t]==s