PageRank algorithm (Python implementation)

Python implements the PageRank algorithm, purely using the Python native module, without using NumPy, scipy. The implementation of this program is relatively primitive, can be optimized more places.

#-*-coding:utf-8-*-import randomn = 8 #八个网页d = 0.85 #阻尼因子为0.85delt = 0.00001# Iteration control variable # two matrix multiply def matrix_multi (A, b): Resul t = [[0]*len (B[0]) for I in Range (Len (a))]for I in range (Len (a)): for J in Range (Len (b[0]): For K in range (len (B)): Result[i ][J] + = A[i][k]*b[k][j] return result# each element of matrix A is multiplied by ndef Matrix_multin (n,a): result = [[1]*len (A[0]) for I in Range (len (A))]f or I in range (len (A)): for J in Range (Len (a[0])): result[i][j] = N*a[i][j]return result# two matrices add def matrix_add (A, b): If Len (a[ 0])!=len (b[0]) and Len (a)!=len (B): Returnresult = [[0]*len (A[0]) for I in Range (Len (a))] for I in range (Len (a)): for J in Ra Nge (Len (a[0)): result[i][j] = A[i][j]+b[i][j]return result def pageRank (A): E = []for i in Range (N): e.append (1) norm = 100N ew_p = []for i in Range (N): New_p.append ([Random.random ()]) R = [[(1-d] *i*1/n] for i in e]while norm > delt:p = New_pne w_p = Matrix_add (R,matrix_multin (D,matrix_multi (a,p))) #P = (1-d) *e/n+d*m ' P pagerank algorithm core norm = 0# Solution Matrix First-order norm for I in range ( N): Norm + = ABS (new_p[i][0]-p[I][0]) print new_p# transfer probability matrix based on adjacency matrix and turn to Def Tran_and_convert (a): result = [[0]*len (A[0]) for I in Range (Len (a))]result_ convert = [[0]*len (A[0]) for I in Range (Len (a))]for I in range (Len (a)): for J in Range (Len (a[0]): result[i][j] = a[i][j]*1. 0/sum (A[i]) for I in range (len (result)): for J in Range (Len (result[0)): Result_convert[i][j]=result[j][i]return result_ Convertdef Main (): A = [[0,1,1,0,0,1,0,0],[0,0,0,1,1,0,0,0],[0,0,0,1,0,1,0,0],[0,0,0,0,0,1,0,0],[1,0,0,1,0,0,1,1], [0,0,0,1,0,0,0,0],[0,0,1,0,0,0,0,0],[0,0,0,1,0,0,1,0]]m = Tran_and_convert (A) PageRank (M) if __name__ = = ' __main__ ': Main ()

PageRank algorithm (Python implementation)