I would like to give some feedback about.
From: https://checkio.org/mission/oil-pie/solve/

On test 4 of extras my code yields a fraction of 219096391762401/1721432812270561
yet the answer the code is looking for is 2.4183843043037004e+21/1.9001162276662057e+22.
The decimal representation of each of these fractions is 0.12727559867 so I believe my code to be correct.

import fractions
def add(x,y): # add two fractions [x[0],x[1]] and [y[0],y[1]]
t=x[0]*y[1]+y[0]*x[1]
b=x[1]*y[1]
c=fractions.gcd(b,t)
t=t/c
b=b/c
return[t,b]
def mul(x,y): # multiply two fractions [x[0],x[1]] and [y[0],y[1]]
t=x[0]*y[0]
b=x[1]*y[1]
c=fractions.gcd(b,t)
t=t/c
b=b/c
return[t,b]
def divide_pie(groups):
x=[1,1] #whole pie
k=groups
k2=[abs(int(i)) for i in k]
l=sum(k2) # the total number of bots
for i in range(len(k)):
if k[i]>0:
x=add(x,[-k[i],l]) # if k[i] is positive we subtract off k[i]/l
if k[i]<0:
x=mul(x,[l+k[i],l]) # if k[i] is negative we subtract off the proper proportion

return x

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Created at: June 2, 2016, 3:41 a.m.; Updated at: June 2, 2016, 5:51 p.m.