[Tutor] rounding

[Sean Perry]

Kim Branson wrote:
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> Hi all,
> 
> heres a quick one for you,
> I have a series of data that I am using dictionaries to build histograms 
> for. I'd like to round the data to the nearest 10, i.e if the value is 
> 15.34  should we round down to 10? and conversely rounding say 19.30 to 
> 20. I'm thinking 15.5 and above would round up. Can anyone point me a at 
> a quick and painless way of achieving this?
>

def round10s(f):
     rem = f % 10
     tens = int(f / 10)

     if rem >= 5.5:
         return (tens + 1.0) * 10.0
     return tens * 10.0

if __name__ == '__main__':
     tests = [15.34, 15.54, 19.65, 2.34, 8.2, 0.0, 20.0]
     for i in tests:
         print "%.2f: %.2f" % (i, round10s(i))

yields
15.34: 10.00
15.54: 20.00
19.65: 20.00
  2.34:  0.00
  8.20: 10.00
  0.00:  0.00
20.00: 20.00