consecutive node sequence and pathlength problem using networkx graph

[bob]

 Let say,I have a conjugated cyclic polygon and its nodes are given
by the list:
   list_p=[a,b,c,d,e,f,g,a,a,b,d,d,d,d,d,c,c,e,e,a,d,d,g]. If X & Y
are any elements in
   a   list_p except d, and Z is also an element of list_p but has
value only d, i.e,
   Z=d. Now,I want to compute the number of  paths with sequence X-Z-
Y consecutive nodes,
   example: a-d-d-e,a-d-d-a, a-d-d-d-g, etc. Consecutive path length
of Z can be 1,2,3,4 or 5.

   To generalize: Find total number of paths with consecutive X-Z-Y
sequence for path length of
   z within range(1,6): or
   (i) X-Z-Y for len(Z)=1
   (ii) X-Z-Y for len(Z)=2
   (iii)X-Z-Y for len(Z)=3
   (iv) X-Z-Y for len(Z)=4
   (v) X-Z-Y for  len(Z)=5

 Is there any easy way to program this using python networkx or
igraph?