page_rank.py

"""
Author: https://github.com/bhushan-borole
"""

"""
The input graph for the algorithm is:

 A B C
A 0 1 1
B 0 0 1
C 1 0 0

"""

graph= [[0, 1, 1], [0, 0, 1], [1, 0, 0]]


classNode:
def__init__(self, name):
self.name=name
self.inbound= []
self.outbound= []

defadd_inbound(self, node):
self.inbound.append(node)

defadd_outbound(self, node):
self.outbound.append(node)

def__repr__(self):
returnf"<node={self.name} inbound={self.inbound} outbound={self.outbound}>"


defpage_rank(nodes, limit=3, d=0.85):
ranks= {}
fornodeinnodes:
ranks[node.name] =1

outbounds= {}
fornodeinnodes:
outbounds[node.name] =len(node.outbound)

foriinrange(limit):
print(f"======= Iteration {i+1} =======")
for_, nodeinenumerate(nodes):
ranks[node.name] = (1-d) +d*sum(
ranks[ib] /outbounds[ib] foribinnode.inbound
 )
print(ranks)


defmain():
names=list(input("Enter Names of the Nodes: ").split())

nodes= [Node(name) fornameinnames]

forri, rowinenumerate(graph):
forci, colinenumerate(row):
ifcol==1:
nodes[ci].add_inbound(names[ri])
nodes[ri].add_outbound(names[ci])

print("======= Nodes =======")
fornodeinnodes:
print(node)

page_rank(nodes)


if__name__=="__main__":
main()