On 03/09/2015 14:32, Marcus Lütolf wrote:
dear pythonistats as a newcomber I want to create a set of lists containing n items, for example n = 3: (['a','b','c'], ['a','d','e'].......). The sequence of items in each list should be different. If the letters 'a'........'z' are used and n = 3 there is a maximum of 301 lists.
The formula for combinations is n! / (r! * (n - r)!) = 26! / (3! * 23!) = 26 * 25 * 24 / (3 * 2 * 1) = 2600, the number given by Peter Otten in his earlier answer using itertools.combinations.
The number for permutations is n! / (n - k)! = 26! / 23! = 26 * 25 * 24 = 15,600.
So what criteria are you using to give 301? -- My fellow Pythonistas, ask not what our language can do for you, ask what you can do for our language. Mark Lawrence _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
