Python 3 floating point rounding

[hpourreza]

When I run 2.2*55 in Python 3, I get 121.00000000000001 instead of 121.0 that is on the course website (01_numpy). I think the output on the course website is from Python 2 that prints 121.0.

[rgaiacs]

@hpourreza Thanks for the issue. Could you send a pull request to fix it?

[neon-ninja]

See https://docs.python.org/3/tutorial/floatingpoint.html -
"Historically, the Python prompt and built-in repr() function would choose the one with 17 significant digits, 0.10000000000000001. Starting with Python 3.1, Python (on most systems) is now able to choose the shortest of these and simply display 0.1."

However, it seems I see the opposite behaviour, the only way to get 121.0 is to evaluate print(2.2*55) on python2. Any other condition (executed at prompt, or executed in python3) results in 121.00000000000001

print(2.2*55) on python 2.7.10 on ideone: http://ideone.com/WYcuze = 121.0
evaluate at prompt on python 2.7.10 on repl.it: https://repl.it/F26E/0 = 121.00000000000001
print(2.2*55) on python 3.4 on ideone: http://ideone.com/DCQgI6 = 121.00000000000001