如果该子列表满足条件，我需要从Python列表中删除子列表

Question

如果子列表中的第二个值为无，我想将其从父列表中弹出，但是我得到的索引超出了范围错误。

Error: 

    Runtime error 
    Traceback (most recent call last): 
    File "<string>", line 2, in <module> 
    IndexError: list index out of range 



listSeq=[[134, None, datetime.datetime(2016, 2, 12, 0, 0)], [135, None, datetime.datetime(2016, 2, 12, 0, 0)], [136, None, datetime.datetime(2016, 2, 12, 0, 0)], [138, 1, datetime.datetime(2016, 2, 12, 0, 0)], [139, None, datetime.datetime(2016, 2, 12, 0, 0)], [140, None, datetime.datetime(2016, 2, 12, 0, 0)], [141, None, datetime.datetime(2016, 2, 12, 0, 0)], [142, 3, datetime.datetime(2016, 2, 12, 0, 0)], [144, None, datetime.datetime(2016, 2, 12, 0, 0)], [145, 2, datetime.datetime(2016, 2, 12, 0, 0)]] 

for x in range(len(listSeq)): 
    if listSeq[x][1]!=None: 
     listSeq.pop(x) 

这里是我使用的解决方案，它的工作原理，到目前为止，虽然我只测试了两遍，我还在审查记录，以确保其工作正常。

import datetime 
import arcpy 
import os 
arcpy.env.overwriteOutput=True 
mxd=arcpy.mapping.MapDocument("CURRENT") 
outWrkspc=r"c:\Project_Status" 
fields=["RNG","SEC","STD_DESCRIPTION","AREA_SF"] 
df=arcpy.mapping.ListDataFrames(mxd,"Layers")[0] 
listLayers=arcpy.mapping.ListLayers(mxd,"LD_BOUNDARY_POLY",df)[0] 


nameDate=datetime.date.today() 
dupTable=os.path.join(outWrkspc,str(listLayers)+"_"+str(nameDate)) 
arcpy.FindIdentical_management("LD_BOUNDARY_POLY",dupTable,fields,output_record_option="ONLY_DUPLICATES") 
arcpy.AddJoin_management("LD_BOUNDARY_POLY","OBJECTID",dupTable,"IN_FID") 
listSeq=[] 
maxId=[] 
keepId=[] 
keepListIndex=[] 
cursor=arcpy.da.SearchCursor("LD_BOUNDARY_POLY","*") 
for row in cursor: 
    listSeq.append([row[0],row[-1],row[-18]]) 
for x in range(len(listSeq)): 
    if listSeq[x][1]is not None: 
     keepId.append(listSeq[x]) 


for x in keepId: 
    if not x[1] in keepListIndex: 
     keepListIndex.append(x[1]) 

for z in keepListIndex: 

    currenTimetList=[] 

    for y in keepId: 

     if z==y[1]: 
      currenTimetList.append(y[2]) 
    maxTime=max(currenTimetList) 
    maxId.append([maxTime,z]) 
delList=[] 

for x in maxId: 
    for n in keepId: 
     if x[0]!=n[2] and x[1]==n[1]: 
      delList.append(n[0]) 

arcpy.RemoveJoin_management("LD_BOUNDARY_POLY") 

for x in delList: 
    whereClause="""OBJECTID = %s"""%x 
    with arcpy.da.UpdateCursor("LD_BOUNDARY_POLY","OBJECTID",whereClause) as uc: 
     for row in uc: 
      uc.deleteRow() 

Answer 1

它通常是更好地使你希望保留项目的一个新的列表来过滤列表。

listSeq = [ 
    [134, None, datetime.datetime(2016, 2, 12, 0, 0)], 
    [135, None, datetime.datetime(2016, 2, 12, 0, 0)], 
    [136, None, datetime.datetime(2016, 2, 12, 0, 0)], 
    [138, 1, datetime.datetime(2016, 2, 12, 0, 0)], 
    [139, None, datetime.datetime(2016, 2, 12, 0, 0)], 
    [140, None, datetime.datetime(2016, 2, 12, 0, 0)], 
    [141, None, datetime.datetime(2016, 2, 12, 0, 0)], 
    [142, 3, datetime.datetime(2016, 2, 12, 0, 0)], 
    [144, None, datetime.datetime(2016, 2, 12, 0, 0)], 
    [145, 2, datetime.datetime(2016, 2, 12, 0, 0)] 
] 

listSeq[:] = [x for x in listSeq if x[1] is not None]