My function running into a TypeError

[Yozuru]

Hello good people of Byte,

I am running into a

TypeError: unsupported operand type(s) for -: 'str' and 'int'

For example when I run:

realdate(['2012', '12, '12])

The error occurs. This is what I have for my code:

def leapyear(y): # Auxiliary Function
    if (y%400 == 0) or (y%4 == 0): return True
    elif (y%100 == 0): return False
    else: return False
 
# Q5a ----------------------
 
def realdate(date): # Format [y, m, d]
    D = ['y', 'm', 'd'] # List for date
    Mon_len_non = [0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31] # Non-leap
    Mon_len_leap = [0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31] # Leap-year
    s = 0 # Non-leapyear
    x = D[2]-1 # Leapyear
    for i in range(1, D[1]):    x += Mon_len_non[i]
    return True
    for i in range(1, D[1]):    x += Mon_len_leap[i]
    return True
    if D[1] == 0 or D[1] < 0:   return False
    if D[2] == 0 or D[2] < 0:   return False
    if D[1] > 12:   return False
    if D[0] >= 2012:
        for i in range(2012, D[0]): s += 365 + leapyear(i)
        return True
    else:   # D[0] < 2012
        for i in range(D[0], 2012): s += 365 + leapyear(i)
        return True

Many thanks for any clarification and help you can provide to me.

[Rabbit]

You're trying to do a subtraction on a string and an integer.

[bvdet]

Yozuru,

I cannot follow what you are trying to do with your code. Are you validating the year, month and date? First off, year 1900 is not a leap year because 1900%400 leaves a remainder but your function returns True. I believe the following uses the correct logic:

def isLeap(yr):
    if not yr % 4 and (yr % 100 or not yr % 400):
        return True
    return False

Here's how I would approach the code to determine if the year, month and day of month integers were valid:
Define function isValidYMD with arguments y, m, and d def isValidYMD(y,m,d):
Define a list of last days of the month for leap year and non-leap year as in

    # not leap year
    daysList1 = [31,28,31,30,31,30,31,31,30,31,30,31]
    # leap year
    daysList2 = [31,29,31,30,31,30,31,31,30,31,30,31]

Check to see if month is between 1 and 12

if 1 <= m <= 12:

If so, assign list of leap year days to a temporary identifier if isLeap(y) returns True or assign list of non-leap year days to a temporary identifier if isLeap(y) returns False.
If d is between 1 and tempList[m-1], return True.

You are done. You may want to add the statement return False otherwise the function will return None if the conditions are not met.

[dwblas]

Notice the difference between the two variables below

is_a_string="2012"
is_an_int = 2012
 
print is_a_string, type(is_a_string)
print is_an_int, type(is_an_int)
print "adding", is_an_int + is_a_string