obsexchange: avoid importing io/StringIO module with a different name
Since we're not interested in the whole module, let's shorten the imports and
aviod the lint warnings.
Otherwise pep8-naming complains:
- import io as StringIO: N812 lowercase imported as non lowercase
- import StringIO as io: N813 camelcase imported as lowercase
syntax: re
/figures/[^/]+\.png$
^html/
\.pyc$
~$
\.swp$
\.orig$
\.rej$
^tests/.*\.err$
^tests/easy_run.sh$
^build/
^dist/
^MANIFEST$
^docs/tutorials/.*\.rst$
\.ico$
tests/\.testtimes
^docs/training/graphs/
^docs/training/html/
^docs/training/index.html
^docs/training/graphviz-images/
^docs/training/img/
^docs/training/output/
^docs/training/pandocfilters/