Last decimal digit precision changes in different call of same generator function [python]

I created this generator function:

def myRange(start,stop,step):
    r = start
    while r < stop:
        yield r
        r += step

and I use it in two different ways. 1st:

for x in myRange(0,1,0.1):
    print x

Result:

0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0

2nd way to call the function:

a = [x for x in myRange(0,1,0.1)]

which results in:

[0, 0.1, 0.2, 0.30000000000000004, 0.4, 0.5, 0.6, 0.7, 0.7999999999999999, 0.8999999999999999, 0.9999999999999999]

Why are the values generated different?

It is not the order in which you called your generator, but the way you are presenting the numbers that caused this change in output.

You are printing a list object the second time, and that's a container. Container contents are printed using repr(), while before you used print on the float directly, which uses str()

repr() and str() output of floating point numbers simply differs:

>>> lst = [0, 0.1, 0.2, 0.30000000000000004, 0.4, 0.5, 0.6, 0.7, 0.7999999999999999, 0.8999999999999999, 0.9999999999999999]
>>> print lst
[0, 0.1, 0.2, 0.30000000000000004, 0.4, 0.5, 0.6, 0.7, 0.7999999999999999, 0.8999999999999999, 0.9999999999999999]
>>> for elem in lst:
...     print elem
... 
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
>>> str(lst[3])
'0.3'
>>> repr(lst[3])
'0.30000000000000004'

repr() on a float produces a result that'll let you reproduce the same value accurately. str() rounds the floating point number for presentation.