Question

I am writing a program in python that will take user birthday input and output their western and chinese zodiac sign. Right now I am just trying to get the Chinese sign working. This is my code so far:

ZODIAC = [(1900, "Rat"), (1901, "Ox"), (1902, "Tiger"), (1903, "Rabbit"), (1904\
, "Dragon"), (1905, "Snake"), (1906, "Horse"), (1907, "Sheep"), (1908, "Monkey"\
), (1909, "Rooster"), (1910, "Dog"), (1911, "Pig")]

def getChineseZodiac(year):
    for i in ZODIAC:
        if (year - ZODIAC[i]) % 12 == 0:
            return ZODIAC[i]

year = input("Enter a year: ")
getChineseZodiac(year)

What I hope for this code to do is to run through each of those years in ZODIAC and find a match with modulus 0, and then return the string attached. But the error I get is TypeError: list indices must be integers, not tuple. How do I solve this?
Am I supposed to be using some other format for ZODIAC?

Answer 1

The exception you are getting is because of the way you are indexing the list. for i in ZODIAC sets i to a member of ZODIAC, not to an index. You can’t then use ZODIAC[i] and have it make sense. Instead, use i directly (in this case, by using i[0] and i in place of the two cases where you were using ZODIAC[i]). Or alternatively, if you do want to iterate over indexes, change your loop to use for i in range(len(ZODIAC)).

However, the whole problem can be simplified. Since the signs in your list are in order, you can do just a single modulus calculation and use it as an index into the list, rather than iterating over the list values and testing each one:

def getChineseZodiac(year):
    index = (year - ZODIAC[0][0]) % 12
    return ZODIAC[index]       # or ZODIAC[index][1], depending on what you want