The answer to my table of elements interview question.

interview_answer2.py

class TableOfElements(object):
    @staticmethod
    def symbols(word):
        symbols = set()
        for i, l in enumerate(word):
            for l2 in word[i + 1:]:
                sym = l.upper() + l2.lower()
                if sym not in symbols:
                    symbols.add(sym)
                    yield sym
                    
    def __init__(self):
        self.element_symbols = {}
        self.reverse_symbols = {}
        return
    
    def add(self, element):
        if element in self.element_symbols:
            return False
        
        for sym in self.symbols(element):
            if sym not in self.reverse_symbols:
                self.element_symbols[element] = sym
                self.reverse_symbols[sym] = element
                return True
                
        return False
        
    def symbol_table(self):
        return self.element_symbols

elements = ['Foo', 'Bar', 'Baz', 'Lorem', 'Ipsum', 'Earth', 'Wind', 'Fire']

toe = TableOfElements()

for e in elements:
    toe.add(e)
    
print toe.element_symbols