Hello,
Using netcdf module with Python 3, I encountered the following trace :

[...]
File "/usr/local/lib/python3.4/site-packages/scipy/io/netcdf.py", line 233, in close
self.flush()
File "/usr/local/lib/python3.4/site-packages/scipy/io/netcdf.py", line 322, in flush
self._write()
File "/usr/local/lib/python3.4/site-packages/scipy/io/netcdf.py", line 334, in _write
self._write_var_array()
File "/usr/local/lib/python3.4/site-packages/scipy/io/netcdf.py", line 380, in _write_var_array
self._write_var_metadata(name)
File "/usr/local/lib/python3.4/site-packages/scipy/io/netcdf.py", line 401, in _write_var_metadata
self._write_att_array(var._attributes)
File "/usr/local/lib/python3.4/site-packages/scipy/io/netcdf.py", line 363, in _write_att_array
self._write_values(values)
File "/usr/local/lib/python3.4/site-packages/scipy/io/netcdf.py", line 475, in _write_values
if isinstance(values, basestring):
NameError: name 'basestring' is not defined

Apparently, 'basestring' type is not used anymore in Python 3.
Here is a tip to avoid the problem : oxplot/fysom#1

Regards,