Gettig错误：类型为…的对象没有len（）

Question

我试图从Python的NX软件中打开的工作部件文件获取PMI计数，但得到错误：

TypeError: object of type 'NXOpen.Annotations.PmiCollection' has no len()

代码：

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文档链接：https://docs.plm.automation.siemens.com/data_services/resources/nx/11/nx_api/custom/en_US/nxopen_python_ref/NXOpen.Annotations.PmiCollection.html

等效vb代码：http://nxjournaling.com/content/find-out-if-part-has-any-pmi

Answer 1

下面的代码给出了活动部件的PMI计数，并在计数更改时断言（这里是3）：

lw = theSession.ListingWindow
lw.Open()
# Custom code starts to get PMI count in part and check
theSession  = NXOpen.Session.GetSession()
theParts = theSession.Parts
theWorkPart = theParts.Work
allPMIObjects = theWorkPart.PmiManager.Pmis
i = 0
for p in allPMIObjects:
    i = i + 1
lw.WriteLine(str(i))
lw.Close()

#if PMI count is changed from 3, raise AssertionError:
assert i == 3