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我是 Jython 的新手。我正在尝试通过 Java 程序(使用 Jython)执行 python 脚本。在 python 脚本中,我试图调用一些外部库(称为 petl)的方法。当我尝试使用 python (As: python script.py) 执行脚本时,它执行没有任何问题。但是,当我尝试使用 Jython(作为:jython script.py)访问脚本时,它给了我以下错误。

PS:我可以毫无问题地运行简单的python脚本。但是当我尝试通过脚本访问外部库函数时,它给了我一个错误。

谁能给我一个解决方法或一些建议?提前致谢。

Python脚本:

import petl as etl

table1 = etl.fromcsv('Books.csv')
table2 = etl.sort(table1, 'ACCOUNT_ID')
etl.tocsv(table2, source='NewBooks.csv',encoding='utf-8')

错误堆栈:

Traceback (most recent call last):
  File "test1.py", line 5, in <module>
    etl.tocsv(table2, source='NewBooks.csv',encoding='utf-8')
  File "C:\Jython\Lib\site-packages\petl\io\csv.py", line 106, in tocsv
    tocsv_impl(table, source=source, encoding=encoding, errors=errors,
  File "C:\Jython\Lib\site-packages\petl\io\csv_py2.py", line 50, in tocsv_impl
    _writecsv(table, source=source, mode='wb', **kwargs)
  File "C:\Jython\Lib\site-packages\petl\io\csv_py2.py", line 74, in _writecsv
    for row in rows:
  File "C:\Jython\Lib\site-packages\petl\transform\sorts.py", line 271, in _iter
nocache
    hdr = next(it)
  File "C:\Jython\Lib\site-packages\petl\io\csv_py2.py", line 30, in __iter__
    codec = getcodec(self.encoding)
  File "C:\Jython\Lib\site-packages\petl\io\base.py", line 12, in getcodec
    codec = codecs.lookup(encoding)
        at org.python.core.codecs.normalizestring(codecs.java:62)
        at org.python.core.codecs.access$200(codecs.java:29)
        at org.python.core.codecs$CodecState.lookup(codecs.java:1695)
        at org.python.core.codecs.lookup(codecs.java:58)
        at org.python.modules._codecs.lookup(_codecs.java:57)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:601)

java.lang.NullPointerException: java.lang.NullPointerException
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1 回答 1

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在调用 fromcsv() 和 tocsv() 函数时,您必须显式传递编码值。

import petl as etl

table1 = etl.fromcsv(source='Books.csv',encoding='utf-8')
table2 = etl.sort(table1, 'ACCOUNT_ID')
etl.tocsv(table2, source='NewBooks.csv',encoding='utf-8')
于 2015-05-26T11:25:55.127 回答