Mathematical Combination – Python

The idea is to print all the different combinations from a series of numbers in a list (order not important). This script will be used to automate the comparison of 40+ networks on a list :D

So, if we start with a series of 1 to 5, what we want to get is

1 2
1 3    2 3
1 4    2 4    3 4
1 5    2 5    3 5    4 5

So here is the python code

# This is the list with all the numbers
numberList=[1,2,3,4,5]

# This is where we find the length of the list (how many items are in there)
listLength=len(numberList)

# we begin the loop for the first digit
for i in range(1,listLength):
	# we then loop the second digit
	for i2 in range(i,listLength):
		# we want to start with 0 so we do a -1
		print numberList[i-1],numberList[i2]

which returns

1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5

just to make sure we got the right answer, we can turn it into a graph…and it should look like this (0 is 1, 1 is 2, and so on)…