CODEWITHSUNDEEP
pythonloops
user979616
user979616

Reputation: 273

Regarding summation with a for loop

I'm trying to get the user to input a birth date and then add the individual ints in those numbers. Also, if a sum of any of these digits is greater than or equal to 10, the loop repeats and the process runs again for the value. Here's my code so far

if (sumYear >= 10):
    sumYear2=0
    for num in str(sumYear):
        sumYear2 += int(num)
print(sumYear2)

This works however I think it would be better done as a loop. And if there's some way I won't have to use something like sumYear2 that would be great. Note, I don't think I can use the sum() function.

Thanks guys for the help. I'm having an issue though. I'm not sure why this code isn't being evaluated when I provide the month as 02 and the day as 30

while True:
        year=input("Please enter the year you were born: ")
        month=input("Please enter the month you were born: ")
        day=input("Please enter the day you were born: ")
        if(int(month)==2 and int(day)<=29):
            break
        elif(int(month)==1 or 3 or 5 or 7 or 8 or 10 or 12 and int(day)<=31 ):
            break
        elif(int(month)==4 or 6 or 9 or 11 and int(day)<=30):
            break
        else:
            print("Please enter a valid input")

Upvotes: 1

Views: 158

Answers (3)

jfs
jfs

Reputation: 414079

@Ignacio Vazquez-Abrams's answer provides the formula. But if there were none then your code as a loop without using sumYear2 could look like:

while sumYear >= 10:
      sumYear = sum(map(int, str(sumYear)))

If you're not allowed to use sum (a homework) then:

while sumYear >= 10:
      s = 0
      for d in str(sumYear):
          s += int(d)
      sumYear = s

For the second question assuming Python 3:

while True:
    try:
        year  = int(input("Please enter the year you were born: "))
        month = int(input("Please enter the month you were born: "))
        day   = int(input("Please enter the day you were born: "))
        birthday = datetime.date(year, month, day)
    except ValueError as e:
        print("error: %s" % (e,))
    else:
        break

If you are not allowed to use try/except then:

year  = get_int("Please enter the year you were born: ",
                datetime.MINYEAR, datetime.MAXYEAR)
month = get_int("Please enter the month you were born: ",
                 1, 12)
day   = get_int("Please enter the day you were born: ",
                1, number_of_days_in_month(year, month))
birthday = datetime.date(year, month, day)

Where get_int():

def get_int(prompt, minvalue, maxvalue):
    """Get an integer from user."""
    while True:
        s = input(prompt)
        if s.strip().isdigit():
           v = int(s)
           if minvalue <= v <= maxvalue:
              return v
        print("error: the input is not an integer in range [%d, %d]" % (
            minvalue, maxvalue))

And number_of_days_in_month():

# number of days in a month disregarding leap years
ndays = [0]*13
ndays[1::2] = [31]*len(ndays[1::2])  # odd months
ndays[::2] = [30]*len(ndays[::2])    # even months
ndays[2] = 28 # February
ndays[8] = 31 # August 
# fill other months here ...

def number_of_days_in_month(year, month):
    return ndays[month] + (month == 2 and isleap(year))

Upvotes: 1

Wai Yip Tung
Wai Yip Tung

Reputation: 18744

You can do this

>>> d=123456
>>> sum(int(c) for c in str(d))
21

Upvotes: 0

Ignacio Vazquez-Abrams
Ignacio Vazquez-Abrams

Reputation: 798486

Too much work.

singledigitsum = (int(inputvalue) - 1) % 9 + 1

Note that this will fail for numbers less than 1.

Upvotes: 2

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