In [1]: 
from time import sleep

x = 0.0

while x != 1.0:
    x += 0.1
    print repr(x)
    
    sleep(0.1)

0.1
0.2
0.30000000000000004
0.4
0.5
0.6
0.7
0.7999999999999999
0.8999999999999999
0.9999999999999999
1.0999999999999999
1.2
1.3
1.4000000000000001
1.5000000000000002
1.6000000000000003
1.7000000000000004
1.8000000000000005
1.9000000000000006
2.0000000000000004
2.1000000000000005
2.2000000000000006
2.3000000000000007
2.400000000000001
2.500000000000001
2.600000000000001
2.700000000000001
2.800000000000001
2.9000000000000012
3.0000000000000013
3.1000000000000014
3.2000000000000015
3.3000000000000016
3.4000000000000017
3.5000000000000018
3.600000000000002

---------------------------------------------------------------------------
KeyboardInterrupt                         Traceback (most recent call last)
<ipython-input-1-83e244af505a> in <module>()
      7     print repr(x)
      8 
----> 9     sleep(0.1)

KeyboardInterrupt:
In []: