logging unicode error

log.txt

2015-01-05 16:01:13,885	INFO	getting patient data for patient set 64969
Traceback (most recent call last):
  File "/usr/local/heron_extract/cdr2edc/dfbuilder.py", line 1033, in <module>
    _trusted_main()
  File "/usr/local/heron_extract/cdr2edc/dfbuilder.py", line 1031, in _trusted_main
    gethostname=socket.gethostname)
  File "/usr/local/heron_extract/cdr2edc/dfbuilder.py", line 951, in main
    params['label'], concepts, filename, patient_set)
  File "/usr/local/heron_extract/cdr2edc/dfbuilder.py", line 801, in __call__
    out = dest.export(job)
  File "/usr/local/heron_extract/cdr2edc/dfbuilder.py", line 670, in export
    self.export_data(dest_star, job)
  File "/usr/local/heron_extract/cdr2edc/dfbuilder.py", line 633, in export_data
    q, data = job.patient_data()
  File "/usr/local/heron_extract/cdr2edc/dfbuilder.py", line 257, in patient_data
    account.execute(var_ins, var_bind)
  File "/usr/local/heron_extract/lib/python2.6/site-packages/sqlalchemy/engine/base.py", line 1752, in execute
    return connection.execute(statement, *multiparams, **params)
  File "/usr/local/heron_extract/lib/python2.6/site-packages/sqlalchemy/engine/base.py", line 729, in execute
    return meth(self, multiparams, params)
  File "/usr/local/heron_extract/lib/python2.6/site-packages/sqlalchemy/sql/elements.py", line 321, in _execute_on_connection
    return connection._execute_clauseelement(self, multiparams, params)
  File "/usr/local/heron_extract/lib/python2.6/site-packages/sqlalchemy/engine/base.py", line 826, in _execute_clauseelement
    compiled_sql, distilled_params
  File "/usr/local/heron_extract/lib/python2.6/site-packages/sqlalchemy/engine/base.py", line 958, in _execute_context
    context)
  File "/usr/local/heron_extract/lib/python2.6/site-packages/sqlalchemy/engine/base.py", line 1163, in _handle_dbapi_exception
    util.reraise(*exc_info)
  File "/usr/local/heron_extract/lib/python2.6/site-packages/sqlalchemy/engine/base.py", line 928, in _execute_context
    context)
  File "/usr/local/heron_extract/lib/python2.6/site-packages/sqlalchemy/dialects/oracle/cx_oracle.py", line 941, in do_executemany
    cursor.executemany(statement, parameters)
UnicodeEncodeError: 'ascii' codec can't encode character u'\xbf' in position 77: ordinal not in range(128)