python - python-weka 包装器中的运行时错误

Question

我编写了以下代码来在 python 和 weka 之间建立连接，然后尝试对加载的数据进行聚类。第一次执行时它工作正常，但是当我尝试在同一 session 中第二次运行此代码时，它给出了一个错误。

jvm.start()
loader = Loader(classname="weka.core.converters.CSVLoader")
data = loader.load_file("/C:/Users/swati/Desktop/MTP_FINAL/Music_recommendation/recommendation/matrix2.csv")

convert = Filter(classname="weka.filters.unsupervised.attribute.NumericToNominal")
convert.inputformat(data)
data = convert.filter(data)
#print data

clusterer = Clusterer(classname="weka.clusterers.SimpleKMeans", options=["-N", "6"])
clusterer.build_clusterer(data)
#print(clusterer)
ans1=[]
for i in range(0,data.num_instances):
    ans1.append(clusterer.cluster_instance(data.get_instance(i)))

n = data.num_instances
jvm.stop()

以下是错误。第二次无法启动jvm。请帮助我解决这个问题。如何纠正这个问题。

RuntimeError at /

Failed to start Java VM

Request Method:     GET
Request URL:    http://127.0.0.1:8000/
Django Version:     1.7.4
Exception Type:     RuntimeError
Exception Value:    

Failed to start Java VM

Exception Location:     C:\Python27\lib\site-packages\javabridge\jutil.py in start_vm, line 259
Python Executable:  C:\Python27\python.exe
Python Version:     2.7.9
Python Path:    

['C:\\Users\\swati\\Desktop\\MTP_FINAL\\Music_recommendation',
 'C:\\Python27\\lib\\site-packages\\setuptools-12.0.5-py2.7.egg',
 'C:\\Python27\\lib\\site-packages\\mysql_python-1.2.5-py2.7-win32.egg',
 'C:\\Windows\\system32\\python27.zip',
 'C:\\Python27\\DLLs',
 'C:\\Python27\\lib',
 'C:\\Python27\\lib\\plat-win',
 'C:\\Python27\\lib\\lib-tk',
 'C:\\Python27',
 'C:\\Python27\\lib\\site-packages']

Answer 1

jvm.stop() 方法只是包装对 javabridge.kill_vm() 方法的调用。根据javabridge documentation ，一旦 JVM 被杀死，就无法再次启动它。通常，您会在调用 main 方法之前和之后启动和停止 JVM，类似于:

import traceback
import weka.core.jvm as jvm

def main():
    # cool stuff happening here
    pass

if __name__ == "__main__":
    try:
        jvm.start()
        main()
    except Exception, e:
        print(traceback.format_exc())
    finally:
        jvm.stop()