use
by the way there are instructions on installation on http://biom-format.org/
pip install biom-format
or if you want to download the package and install it from your pc, download the wheel file biom_format-2.1.6-cp27-cp27m-macosx_10_7_x86_64.whl (from pypi https://pypi.python.org/pypi/biom-format/2.1.6) and pip install biom_format-2.1.6-cp27-cp27m-macosx_10_7_x86_64.whl
by the way there are instructions on installation on http://biom-format.org/