Currently I am creating a function called randomwalk
that takes as input the set edges
, a teleport probability a
and a positive integer iters
and performs the random walk.
Starting from any page, the function will randomly follow links from one page to the next, teleporting to a completely random page with probability a
at each iteration.
It should also store all visited states and eventually create a histogram of the frequency by which each page was visited. This histogram is what the randomwalk function will return
This is what I have so far, I'm getting an Unhashable Type error though for list. Here is the list of edges
edges =[[0,1], [1,1], [2,0], [2,2], [2,3], [3,3], [3,4], [4,6], [5,5], [6,6], [6,3]]
def randomWalk(edges, a ,iters):
pages = {edge[0] for edge in edges}
dict_edges = {}
for edge_from, edge_to in edges:
if edge_from not in dict_edges:
dict_edges[edge_from] = [edge_to]
else:
dict_edges[edge_from].append(edge_to)
current_page = random.choice(pages)
visit_counts_dictionary = {page:0 for page in pages}
visit_counts_dictionary[current_page] +=1
for _ in range(iters):
if random.uniform(0,1) < a:
current_page = random.choice(pages)
visit_counts_dictionary[current_page] += 1
else:
current_page = random.choice(dict_edges[current_page])
visit_counts_dictionary[current_page] += 1
print visit_counts_dictionary
print(randomWalk(edges, 0, 10))
How would I fix this?
The reason why you are getting this error is that you cannot use list
as a key in dict
in python. Use tuple
instead:
error_dict = {[1, 2]: "some_data"}
# >>> TypeError: unhashable type: 'list'
correct_dict = {(1, 2): "some_data"}
# no error
The error in you code comes from this line:
pages = list({edges[0] for edge in edges})
You probably made a mistake in edges[0]
, change it to edge[0]
:
pages = list({edge[0] for edge in edges})