Drawing a graph

Hello,

I'm new in Matplotlib and am writing in order to ask a help.
I've developed a little software with Python that, by inserting a
number, calculate a list of couples.

Example

Insert a number: 4
Couples: [[4, 3], [4, 2], [4, 1], [3, 2], [3, 1], [2, 1]]

What I'd like to do is drawing with Matplotlib a graph having as nodes
1, 2, 3, 4 and as edges among the nodes the above couples. (sample
drawing: https://networkx.lanl.gov/)

Can you help me to make this operation please?
My code at the present is the following one.

n = input("Insert a number" )
a = range(n)
p = 0
q = 1
coppie = []
coppia = []
while len(a) - p != 1:
  coppia.append(len(a) - p)
  coppia.append(len(a) - p - q)
  coppie.append(coppia)
  coppia = []
  if len(a) - p - q != 0:
    q = q + 1
  if len(a) - p - q == 0:
    p = p + 1
    q = 1
print coppie

I suppose it is quite easy but in spite of this have some difficulty.
Really many thanks for the help!

Best,
Nico

n = input("Insert a number" )
a = reversed(range(1,n+1))
coppie = [[i,j] for i in a for j in range(1,i)]
print coppie
G = NX.Graph()
for edge in coppie:
  G.add_edge(*edge)
print G.edges()
NX.draw(G)
pylab.savefig(r'c:\temp\temp.eps')

hth,
Alan Isaac

···

On Fri, 26 May 2006, Giandomenico Sica apparently wrote:

Insert a number: 4
Couples: [[4, 3], [4, 2], [4, 1], [3, 2], [3, 1], [2, 1]]
What I'd like to do is drawing with Matplotlib a graph having as nodes
1, 2, 3, 4 and as edges among the nodes the above couples.