# -*- coding: utf-8 -*-
import numpy as np


# Number of nodes in a community 
#
# Usage
#
#   s = n(network, community)
#
# Input
#
#   network - Networkx Graph class instance
#
#   community - List of the IDs of nodes in a community
#
# Output
#
#   s - Number of nodes in a community 
#
def n(network, community):
    s = len(community)
    return s 


# Sum of degrees of nodes in a community   
#
# Usage
#
#   s = vol(network, community)
#
# Input
#
#   network - Networkx Graph class instance
#
#   community - List of the IDs of nodes in a community
#
# Output
#
#   s - Sum of degrees of nodes in a community
#
def vol(network, community):
    s = sum([x[1] for x in network.degree(community)])
    return s
