Python Luigi LocalTarget泡菜

Question

我在Windows 7，通过Anaconda 4.3.17，Luigi 2.4.0，Pandas 0.18，sklearn版本0.18的Python 2.7上运行。在下面，我试图将luigi.LocalTarget输出作为一个腌菜来存储一些不同的对象（使用firstJob），然后在一个依赖的作业（secondJob）中从该腌菜中读取。如果我从命令行运行以下命令，则firstJob成功完成：

“ python -m luigi --module luigiPickle firstJob --date 2017-06-07 --local-scheduler”

但是，如果我尝试运行secondJob，即

“ python -m luigi --module luigiPickle secondJob --date 2017-06-07 --local-scheduler”

我懂了

Traceback (most recent call last):
  File "C:\Anaconda2\lib\site-packages\luigi-2.4.0-py2.7.egg\luigi\worker.py", l
ine 191, in run
    new_deps = self._run_get_new_deps()
  File "C:\Anaconda2\lib\site-packages\luigi-2.4.0-py2.7.egg\luigi\worker.py", l
ine 129, in _run_get_new_deps
    task_gen = self.task.run()
  File "luigiPickle.py", line 41, in run
    ret2 = pickle.load(inFile)
  File "C:\Anaconda2\lib\pickle.py", line 1384, in load
    return Unpickler(file).load()
  File "C:\Anaconda2\lib\pickle.py", line 864, in load
    dispatch[key](self)
  File "C:\Anaconda2\lib\pickle.py", line 1096, in load_global
    klass = self.find_class(module, name)
  File "C:\Anaconda2\lib\pickle.py", line 1130, in find_class
    __import__(module)
ImportError: No module named frame

似乎luigi由于无法识别pandas.DataFrame（）对象（可能是范围问题？）而无法读取泡菜。

import luigi
import pandas as pd
import pickle
from sklearn.linear_model import LinearRegression

class firstJob(luigi.Task):
    date = luigi.DateParameter()

    def requires(self):
        return None

    def output(self):
        return luigi.LocalTarget('%s_first.pickle' % self.date)

    def run(self):
        ret = {}
        ret['a'] = pd.DataFrame({'a': [1, 2], 'b': [3, 4]})
        ret['b'] = pd.DataFrame({'a': [3, 4], 'd': [0, 0]})
        ret['c'] = LinearRegression()
        outFile = self.output().open('wb')
        pickle.dump(ret, outFile, protocol=pickle.HIGHEST_PROTOCOL)
        outFile.close()

class secondJob(luigi.Task):
    date = luigi.DateParameter()

    def requires(self):
        return firstJob(self.date)

    def output(self):
        return luigi.LocalTarget('%s_second.pickle' % self.date)

    def run(self):
        inFile = self.input().open('rb')
        ret2 = pickle.load(inFile)
        inFile.close()

if __name__ == '__main__':
    luigi.run()

Answer 1

luigi open命令不适用于二进制的b标志，它将其从选项字符串中删除。（不知道为什么）。最好只使用带有path属性的标准打开：

open(self.input().path, 'rb')和open(self.output().path, 'wb')。