How can I complete this python program that implements the Anonymous Gregorian Computus algorithm to-CodePudding

I have tried to compute the date Easter falls on a particular year with this python program using the Anonymous Gregorian Computus Algorithm but I keep getting one error. My code block outputs the right result but I am finding it difficult to attach 'st' to the numbers in the 'st' list.

# Read the input from the user
year = int(input("Please enter a year to calculate the date of Easter: "))

a = year % 19
b = year // 100
c = year % 100
d = b // 4
e = b % 4
f =( b   8) // 25
g = (b - f   1) // 3
h =  ((19 * a)   b - d - g   15) % 30
i = c // 4
k = c % 4
l = (32   (2 * e)   (2 * i) - h - k) % 7
m = (a   (11 * h )   (22 * l)) // 451
month = (h   l - (7 * m)   (114)) // 31
day = 1   (( h   l - (7 * m)   (114)) % 31)

st = ['1', '21', '31']
nd = ['2', '22']
rd = ['3', '23']
th = ['4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15', '16', '17', '18', '19', '20', '24', '25', '26', '27', '28', '29', '30']

if day in st:
    print("In the year", year, "Easter will fall on the", str(day)   "st", "of", month)
elif day in nd:
    print("In the year", year, "Easter will fall on the", str(day)   "nd", "of", month)
elif day in rd:
    print("In the year", year, "Easter will fall on the", str(day)   "rd", "of", month)
else:
    print("In the year", year, "Easter will fall on the", str(day)   "th", "of", month)

Using this algorithm, I have computed for different years to check if my code block is correct but when I compute for years like 2024 and 2040 that have their Easter dates falling on the days in the 'st' list, I keep getting '31th and 1th' instead of '31st and 1st'. I don't know what lines of code I am missing. If you can help me with this or tell me how best to compute this, I will really appreciate it.

PS: I have searched for other similar questions but the ones I have solved were in a totally different language and I didn't find one that used the Anonymous Gregorian Computhus Algorithm to compute the date of Easter.

Thank you.

CodePudding user response：

You can easily see your problem by using the Python interpreter:

$ python3
>>> st = ['1', '21', '31']
>>> 21 in st
False
>>> '21' in st
True

Strings and numbers are different things. You compute a number, so your test has to be with numbers.

$ python3
>>> st = [1, 21, 31]
>>> 21 in st
True

You should use sets instead of lists for inclusion tests. In this case, it doesn't make much difference but it's a good habit to get into in case there are lots of values.