AttributeError：__len__使用ntpath.py和Tkinter.py时出错

Question

当我运行脚本并且它正在更改目录时，我收到以下错误 - 我怎么能修复此错误？

  

Traceback（最近一次调用最后一次）：文件   “L：\ Data_Admin \ QA \ Metadata_python_toolset \ TEST2 \ update_Metadata1e.py”   第17行，in       currentPath = os.path.join（root，directory）文件“C：\ Python26 \ ArcGIS10.0 \ lib \ ntpath.py”，第96行，在连接中       断言len（路径）＆gt; 0文件“C：\ Python26 \ ArcGIS10.0 \ lib \ lib-tk \ Tkinter.py”，第1722行，   的 GETATTR       return getattr（self.tk，attr）AttributeError： len

完整代码

import os, xml, arcpy, shutil, datetime, Tkinter,tkFileDialog
from xml.etree import ElementTree as et 

path=os.getcwd()
RootDirectory=path
arcpy.env.workspace = path
Count=0

Generated_XMLs=RootDirectory+'\GeneratedXML_LOG.txt'
f = open(Generated_XMLs, 'a')
f.write("Log of Metadata Creation Process - Update: "+str(datetime.datetime.now())+"\n")
f.close()

for root, dirs, files in os.walk(RootDirectory, topdown=False):
    #print root, dirs
    for directory in dirs:
        currentPath=os.path.join(root,directory)
        os.chdir(currentPath)
        arcpy.env.workspace = currentPath
        print currentPath
#def Create_xml(currentPath):

        FileList = arcpy.ListFeatureClasses()
        zone="_Zone"

        for File in FileList:
            Count+=1
            FileDesc_obj = arcpy.Describe(File)
            FileNm=FileDesc_obj.file
            check_meta=os.listdir(currentPath)
            existingXML=FileNm[:FileNm.find('.')]
            existingExtension=FileNm[FileNm.find('.'):]
            print "XML: "+existingXML
            #print check_meta
            #if  existingXML+'.xml' in check_meta:
            #newMetaFile='new'
            for f in check_meta:
                if f.startswith(existingXML) and f.endswith('.xml'):
                    print "exists, file name:", f
                    newMetaFile=FileNm+"_2012Metadata.xml"
                    shutil.copy2(f, newMetaFile)
                    break
                else:
                    #print "Does not exist"
                    newMetaFile=FileNm+"_BaseMetadata.xml"

            print "New meta file: "+newMetaFile+ " for: "+File
            if newMetaFile.endswith('_BaseMetadata.xml'):        
                print "calling tkinter"
                root = Tkinter.Tk()
                file = tkFileDialog.askopenfile(parent=root,mode='rb',title='Choose a xml base file to match with: '+File)
                if file != None:
                    metafile=os.path.abspath(file.name)
                    file.close()
                    #print metafile
                    shutil.copy2(metafile,newMetaFile)
                    print "copied"+metafile
                    root.destroy

                else:
                    shutil.copy2('L:\Data_Admin\QA\Metadata_python_toolset\Master_Metadata.xml', newMetaFile)


            print "Parsing meta file: "+newMetaFile
            tree=et.parse(newMetaFile)        
            print "Processing: "+str(File)

            for node in tree.findall('.//title'):
                node.text = str(FileNm)
            for node in tree.findall('.//northbc'):
                node.text = str(FileDesc_obj.extent.YMax)
            for node in tree.findall('.//southbc'):
                node.text = str(FileDesc_obj.extent.YMin)
            for node in tree.findall('.//westbc'):
                node.text = str(FileDesc_obj.extent.XMin)
            for node in tree.findall('.//eastbc'):
                node.text = str(FileDesc_obj.extent.XMax)        
            for node in tree.findall('.//native/nondig/formname'):
                node.text = str(os.getcwd()+"\\"+File)
            for node in tree.findall('.//native/digform/formname'):
                node.text = str(FileDesc_obj.featureType)
            for node in tree.findall('.//avlform/nondig/formname'):
                node.text = str(FileDesc_obj.extension)
            for node in tree.findall('.//avlform/digform/formname'):
                node.text = str(float(os.path.getsize(File))/int(1024))+" KB"
            for node in tree.findall('.//theme'):
                node.text = str(FileDesc_obj.spatialReference.name +" ; EPSG: "+str(FileDesc_obj.spatialReference.factoryCode))
            print node.text
            projection_info=[]
            Zone=FileDesc_obj.spatialReference.name

            if "GCS" in str(FileDesc_obj.spatialReference.name):
                projection_info=[FileDesc_obj.spatialReference.GCSName, FileDesc_obj.spatialReference.angularUnitName, FileDesc_obj.spatialReference.datumName, FileDesc_obj.spatialReference.spheroidName]
                print "Geographic Coordinate system"
            else:
                projection_info=[FileDesc_obj.spatialReference.datumName, FileDesc_obj.spatialReference.spheroidName, FileDesc_obj.spatialReference.angularUnitName, Zone[Zone.rfind(zone)-3:]]
                print "Projected Coordinate system"
            x=0
            for node in tree.findall('.//spdom'):
                for node2 in node.findall('.//keyword'):
                    print node2.text
                    node2.text = str(projection_info[x])
                    print node2.text
                    x=x+1


            tree.write(newMetaFile)

            f = open(Generated_XMLs, 'a')
            f.write(str(Count)+": "+File+"; "+newMetaFile+"; "+currentPath+"\n")
            f.close()

        print "change dir 1"
    print "change dir 2"


    #        Create_xml(currentPath)

Answer 1

os.chdir可能令您感到困惑os.walk。尝试在下一次迭代之前恢复工作目录。

更好的是，如果为chdir定义上下文管理器，则可以使用with语句。 Here's an example，定义了chdir的版本，您可以按如下方式使用：

  for root, dirs, files in os.walk(RootDirectory, topdown=False):
    for directory in dirs:
      currentPath=os.path.join(root,directory)
      with chdir(currentPath):
        # now inside the specified directory
        # after exiting 'with', original directory will be restored