Sorry that I ask this here, because this seems really elementary and is most likely asked before. However, I have been searching and trying for hours and I couldn't find anything that helped me out. I want to write a program that asks for an upper bound and returns a table with pairs of numbers (m,n) such that the sum of of divisors of n (excluding n) equals m, and vice versa.
Now I wrote the following
bound = int(input('upper bound = '))
l = len(str(bound))
for x in range(1,l):
print(' ', end='')
print('m', end=' ')
for y in range(1,l):
print(' ', end='')
print('n', end='')
for i in range(1,bound):
for j in range (1, bound):
if j == i:
break
som_i = 0
som_j = 0
for k in range(1,i):
if i % k == 0:
som_i += k
for l in range(1,j):
if j % l == 0:
som_j += l
if som_i == j and som_j == i:
print('{:{prec}d}'.format(j, prec = l).rstrip(''), end="")
print('{:{prec}d}'.format(i, prec = l+2).lstrip(''), end="")
The problem is that I want the pair to be displayed in tabular form side to side and with the right indentation, depending on the length of the number. Whatever I tried (I read so many treads with similar questions already) Python keeps adding a whitespace.
Can anyone help me out on this? I am really new to Python and I cannot figure this out myself. If relevant, I am using version 3.6.
EDIT:
For example, when I run the program I get:
upper bound = 300
m n
220
284
while I would like to get
upper bound = 300
m n
220 284
And similar for larger inputs.
EDIT2 My question is not a duplicate, since i already tried adding
end=""
which did not work.
The first problem is that you're not using end='' after printing the j value, but you apparently already know about that. You also are using it after printing the n header, which you don't want.
Your edited version fixes the missing end='' after the j print, but then adds one after the i print, which, again, you don't want.
I'm not sure you understand what end='' means, so you're just putting it into your code randomly. That isn't going to get you very far. You can read the docs for print, but the short version is: use end='' when you're printing something that isn't supposed to be the end of a line, like that m header and j value, but don't use it when you're printing something that is supposed to be the end of a line, like that n header and i value.
The second problem is that l is just way too big. After for l in range(1,j):, it's going to be the same value as j, which means it's going to be 219, so you're going to print that 220 filled out to 219 characters, and that 284 filled out to 221 characters. So, unless your terminal is more than 446 characters wide, it's going to scroll across multiple lines and look like a mess. I think what you may want here is to use 3 and 5.
Or, maybe, you have some other variable that's supposed to be 3, and you want to use (let's call that variable x) x and x+2 instead of l and l+2. But I don't see any obvious candidates in your code.
So:
# ... unchanged lines
print('n') # no end='' here
# ... more unchanged lines
# using 3 and 5 instead of l and l+2, and adding end=''
print(('{:{prec}d}'.format(j, prec = 3)).rstrip(''), end='')
print(('{:{prec}d}'.format(i, prec = 5)).lstrip(''))
And now, the output is:
upper bound = 300
m n
220 284