Python don't divide

[SteLu]

Sorry, I am going to copu and paste the post with the tags

Hello!!

I am coding what should be an easy program, to calculate few things. But, unfortunately, the things are not going as I planned.

This is my code:

seq_T4 ='MILKILNEIASIGSTKQK....NTFEDVFGDFHEVTGL'

y = 0
w = 0
f = 0
num_aa = 0

for aa in seq_T4.lower():
    num_aa += 1
    if aa == 'y':
        y += 1
    elif aa == 'w':
        w += 1
    elif aa == 'f':
        f += 1

aa_fluo = y + w + f
ratio = aa_fluo / num_aa

print ('the protein as', num_aa, 'aa, and therefore MW of roughly kDa', (num_aa*650)/1000)
print ('the number or Tyrosine is:', y)
print ('the number or Tryptophan is:', w)
print ('the number or Phenylalanine is:', f)
a = 43/487
print ('the Fluorescent aa / total aa is ', format(ratio,'.5f'))

Output:
('the protein as', 38, 'aa, and therefore MW of roughly kDa', 24)
('the number or Tyrosine is:', 0)
('the number or Tryptophan is:', 0)
('the number or Phenylalanine is:', 3)
('the Fluorescent aa / total aa is ', '0.00000')

---

Print out the numerator and denominator and make sure that's correct. I almost guarantee that's your problem

Hi Afterdarkreader,

I've already tried your suggestion and no luck at all. I've tried several solution, also

print(len(set_T4))

and even

print (43/487)

give as result 0.000000

---

Hello again,

I've used this version of python and Ipython and the script worked perfectly. any guess?

Python 3.5.2 (default, Nov 23 2017, 16:37:01)
Type 'copyright', 'credits' or 'license' for more information
IPython 6.2.1 -- An enhanced Interactive Python. Type '?' for help.