我正在学习使用Fonduer从文本文档中构建知识库。在附件的Jupyter笔记本中进行max_storage_temp_tutorial教程时，尝试执行以下代码时出现了错误：

corpus_parser = Parser(structural=True, lingual=True, visual=True, pdf_path=pdf_path)%time corpus_parser.apply(doc_preprocessor, parallelism=PARALLEL)

以下是我得到的错误信息：

UnicodeEncodeError: 'ascii' codec can't encode character '\uf0b7' in position 6282: ordinal not in range(128)

以下是错误的堆栈跟踪：

[INFO] fonduer.utils.udf - Clearing existing...[INFO] fonduer.utils.udf - Running UDF...---------------------------------------------------------------------------UnicodeEncodeError                        Traceback (most recent call last)<timed eval> in <module>()~/anaconda3/envs/fonduer/lib/python3.6/site-packages/fonduer/utils/udf.py in apply(self, xs, clear, parallelism, progress_bar, count, **kwargs)     48         self.logger.info("Running UDF...")     49         if parallelism is None or parallelism < 2:---> 50             self.apply_st(xs, progress_bar, clear=clear, count=count, **kwargs)     51         else:     52             self.apply_mt(xs, parallelism, clear=clear, **kwargs)~/anaconda3/envs/fonduer/lib/python3.6/site-packages/fonduer/utils/udf.py in apply_st(self, xs, progress_bar, count, **kwargs)     81      82         # Commit session and close progress bar if applicable---> 83         udf.session.commit()     84         if pb:     85             pb.close()~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/orm/session.py in commit(self)    941                 raise sa_exc.InvalidRequestError("No transaction is begun.")    942 --> 943         self.transaction.commit()    944     945     def prepare(self):~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/orm/session.py in commit(self)    465         self._assert_active(prepared_ok=True)    466         if self._state is not PREPARED:--> 467             self._prepare_impl()    468     469         if self._parent is None or self.nested:~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/orm/session.py in _prepare_impl(self)    445                 if self.session._is_clean():    446                     break--> 447                 self.session.flush()    448             else:    449                 raise exc.FlushError(~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/orm/session.py in flush(self, objects)   2252         try:   2253             self._flushing = True-> 2254             self._flush(objects)   2255         finally:   2256             self._flushing = False~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/orm/session.py in _flush(self, objects)   2378         except:   2379             with util.safe_reraise():-> 2380                 transaction.rollback(_capture_exception=True)   2381    2382     def bulk_save_objects(~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/util/langhelpers.py in __exit__(self, type_, value, traceback)     64             self._exc_info = None   # remove potential circular references     65             if not self.warn_only:---> 66                 compat.reraise(exc_type, exc_value, exc_tb)     67         else:     68             if not compat.py3k and self._exc_info and self._exc_info[1]:~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/util/compat.py in reraise(tp, value, tb, cause)    247         if value.__traceback__ is not tb:    248             raise value.with_traceback(tb)--> 249         raise value    250     251 else:~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/orm/session.py in _flush(self, objects)   2342             self._warn_on_events = True   2343             try:-> 2344                 flush_context.execute()   2345             finally:   2346                 self._warn_on_events = False~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/orm/unitofwork.py in execute(self)    384                 while set_:    385                     n = set_.pop()--> 386                     n.execute_aggregate(self, set_)    387         else:    388             for rec in topological.sort(~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/orm/unitofwork.py in execute_aggregate(self, uow, recs)    666                              [self.state] +    667                              [r.state for r in our_recs],--> 668                              uow)    669     670     def __repr__(self):~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/orm/persistence.py in save_obj(base_mapper, states, uowtransaction, single)    179         _emit_insert_statements(base_mapper, uowtransaction,    180                                 cached_connections,--> 181                                 mapper, table, insert)    182     183     _finalize_insert_update_commands(~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/orm/persistence.py in _emit_insert_statements(base_mapper, uowtransaction, cached_connections, mapper, table, insert, bookkeeping)    828     829             c = cached_connections[connection].\--> 830                 execute(statement, multiparams)    831     832             if bookkeeping:~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/engine/base.py in execute(self, object, *multiparams, **params)    946             raise exc.ObjectNotExecutableError(object)    947         else:--> 948             return meth(self, multiparams, params)    949     950     def _execute_function(self, func, multiparams, params):~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/sql/elements.py in _execute_on_connection(self, connection, multiparams, params)    267     def _execute_on_connection(self, connection, multiparams, params):    268         if self.supports_execution:--> 269             return connection._execute_clauseelement(self, multiparams, params)    270         else:    271             raise exc.ObjectNotExecutableError(self)~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/engine/base.py in _execute_clauseelement(self, elem, multiparams, params)   1058             compiled_sql,   1059             distilled_params,-> 1060             compiled_sql, distilled_params   1061         )   1062         if self._has_events or self.engine._has_events:~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/engine/base.py in _execute_context(self, dialect, constructor, statement, parameters, *args)   1198                 parameters,   1199                 cursor,-> 1200                 context)   1201    1202         if self._has_events or self.engine._has_events:~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/engine/base.py in _handle_dbapi_exception(self, e, statement, parameters, cursor, context)   1414                 )   1415             else:-> 1416                 util.reraise(*exc_info)   1417    1418         finally:~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/util/compat.py in reraise(tp, value, tb, cause)    247         if value.__traceback__ is not tb:    248             raise value.with_traceback(tb)--> 249         raise value    250     251 else:~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/engine/base.py in _execute_context(self, dialect, constructor, statement, parameters, *args)   1168                         statement,   1169                         parameters,-> 1170                         context)   1171             elif not parameters and context.no_parameters:   1172                 if self.dialect._has_events:~/anaconda3/envs/fonduer/lib/python3.6/site-packages/sqlalchemy/dialects/postgresql/psycopg2.py in do_executemany(self, cursor, statement, parameters, context)    681             extras.execute_batch(cursor, statement, parameters)    682         else:--> 683             cursor.executemany(statement, parameters)    684     685     @util.memoized_instancemethodUnicodeEncodeError: 'ascii' codec can't encode character '\uf0b7' in position 6282: ordinal not in range(128)

在打印executemany函数的输入时，我发现存在无效的Unicode字符，但我不知道该如何处理。

请注意以下几点：

1. 我已经使用教程中的download_data.sh脚本下载了pdf和html文件

2. 我已经安装了设置文档中提到的所有先决条件

   • Ubuntu 16.04 bash for Windows
   • PostgreSQL 版本：[9.5.13]
   • Poppler Utils 版本：[0.41.0-0ubuntu1.7]
   • Fonduer 版本：[0.2.3]

3. 教程可以在这里找到。

4. 我使用了Windows上的Ubuntu来运行所需的服务

回答：

问题是由于PostgreSQL数据库的编码引起的。Fonduer需要UTF-8编码，而Windows默认使用不同的编码。

我所需要做的就是：

1.删除所需的数据库。

dropdb stg_temp_max

2.创建一个使用UTF-8编码的新数据库。

createdb -E UTF8 -T template0 stg_temp_max