Demonstrating what appears to be a scoping bug in Python 3.5.1

comp_scope_bug.py

from __future__ import print_function

foo = 'bar'

# This works
[foo for _ in range(5)]


# This also works:
class Foo:
    bar = [foo for _ in range(5)]


# This does not work in Python 3.5.1:
class Bar:
    bar = foo
    blah = [bar for _ in range(5)]


print("Success!")

# $ pyenv local 2.7.11
#
# $ python comp_scope_bug.py
# Success!
#
# $ pyenv local 3.5.1
#
# $ python comp_scope_bug.py
# Traceback (most recent call last):
#   File "comp_scope_bug.py", line 13, in <module>
#     class Bar:
#   File "comp_scope_bug.py", line 15, in Bar
#     blah = [bar for _ in range(5)]
#   File "comp_scope_bug.py", line 15, in <listcomp>
#     blah = [bar for _ in range(5)]
# NameError: name 'bar' is not defined