使用 python 查找空值表单形状文件属性字段

Question

我有 100 个来自不同子文件夹的形状文件。我想检查每个形状文件中的 "Population" 字段。如果任何形状文件中的 "Population" 字段是 ["", " ", None] 然后打印这些特定形状文件的名称。

import os  
import fnmatch  
import arcpy  
rootPath = r"C:\Project\layers"   
pattern = 'mig*.shp'   
for root, dirs, files in os.walk(rootPath):   
    for filename in fnmatch.filter(files, pattern):   
        shp = os.path.join(root, filename)  
        if arcpy.ListFields(shp, "Population"):  
            print("{} has Population field".format(shp))   
            with arcpy.da.SearchCursor(shp, ["Population"]) as rows:  
                for row in rows:  
                    if row[0] == ["", " ", None]:  
                        print("{} has a empty value".format(shp))
                    else:
                            print "OK"

脚本可以很好地查找具有人口字段的形状文件名称。但是它无法找到人口字段为空的形状名称。

我得到 "runtime error"。类型错误：字符串索引必须是整数，而不是 str.

Answer 1

我无法准确回答你的问题，但也许这种方法会对你有所帮助：

import arcgisscripting
gp = arcgisscripting.create(9.3)
...
rows = gp.SearchCursor(shp)
row = rows.Next()
while row:
    population = row.GetValue("Population")
    # ... perform check ...
    row = rows.next()

Answer 2

我宁愿将它添加为对你的问题的评论，但我不能。首先，如果你想检查字段是否为空，请更改行：

if row[0] == ["", " ", None]:

至：

if row[0] in ["", " ", None]:

但这是不应导致运行时错误的逻辑错误。还请确保最后一行打印 "OK" 的缩进是正确的。

运行下面的代码，让我们知道运行时错误是否仍然存在。如果是，请提供更多信息（包括错误行）：

import os  
import fnmatch  
import arcpy  
rootPath = r"C:\Project\layers"   
pattern = 'mig*.shp'   
for root, dirs, files in os.walk(rootPath):   
    for filename in fnmatch.filter(files, pattern):   
        shp = os.path.join(root, filename)  
        if arcpy.ListFields(shp, "Population"):  
            print("{} has Population field".format(shp))   
            with arcpy.da.SearchCursor(shp, ["Population"]) as rows:  
                for row in rows:  
                    if row[0] in ["", " ", None]:  
                        print("{} has a empty value".format(shp))
                    else:
                        print "OK"

使用 python 查找空值表单形状文件属性字段

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