Combinations With Two Elements

With python. It's possible to permute elements in a list with this method: def perms(seq): if len(seq) <= 1: perms = [seq] else: perms = [] for

Solution 1:

Consider using the combinations function in Python's itertools module:

>>> list(itertools.combinations('ABC', 2))
[('A', 'B'), ('A', 'C'), ('B', 'C')]

This does what it says: give me all combinations with two elements from the sequence 'ABC'.

Solution 2:

def getCombinations(seq):
    combinations = list()
    for i in range(0,len(seq)):
        for j in range(i+1,len(seq)):
            combinations.append([seq[i],seq[j]])
    return combinations

>>> print(getCombinations(['A','B','C']))
[['A', 'B'], ['A', 'C'], ['B', 'C']]

Solution 3:

Building off your method: Pass in a counter (defaulted to 2) that keeps track of how many more letters to pick. Use this instead of length for the base case.