'''Test the function to extract keys from a format string for a dictionary.'''

def getKeys(formatString):
    '''formatString is a format string with embedded dictionary keys.
    Return a list containing all the keys from the format string.'''

    keyList = list()
    end = 0
    repetitions = formatString.count('{')
    for i in range(repetitions):
        start = formatString.find('{', end) + 1
        end = formatString.find('}', start)
        key = formatString[start : end]
        keyList.append(key)
    return keyList

originalStory = """
Once upon a time, deep in an ancient jungle,
there lived a {animal}.  This {animal}
liked to eat {food}, but the jungle had
very little {food} to offer.  One day, an
explorer found the {animal} and discovered
it liked {food}.  The explorer took the
{animal} back to {city}, where it could
eat as much {food} as it wanted.  However,
the {animal} became homesick, so the
explorer brought it back to the jungle,
leaving a large supply of {food}.

The End
"""

print(getKeys(originalStory))