Question

我有一些最初看起来像这样的代码（它是for循环中迭代查询结果的一部分）：

<DataContract()> _
Public Class PeopleList
    <DataMember(Name:="people")> _
    Public People_List As List(Of People)
End Class

<DataContract()> _
Public Class People
    <DataMember(Name:="name")> _
    Public Person_Name As String

    <DataMember(Name:="att")> _
    Public Attempts As String
End Class

Public Sub ScrapeFile()
    Try
        Dim thisScrape As New PeopleList
        thisScrape = DirectCast(JSONSerialization.jsonDeserializeURI(Of PeopleList)("http://www.sitenotusedyet.com"), PeopleList)
    Catch ex As Exception
        MsgBox("Shit")
    End Try
End Sub

Public Shared Function JsonDeserialize(Of T)(jsonString As String) As T
        Dim ser As New DataContractJsonSerializer(GetType(T))
        Dim ms As New MemoryStream(Encoding.UTF8.GetBytes(jsonString))
        Dim obj As T = DirectCast(ser.ReadObject(ms), T)
        Return obj
End Function

Public Shared Function jsonDeserializeURI(Of T)(ByVal strURI As String) As T
        Dim strHTML As String
        Dim objWC As New System.Net.WebClient
        Dim obj As T
        Try
            obj = JSONSerialization.JsonDeserialize(Of T)("{""people"":{""00-0029619"":{""name"":""J.Lane"",""att"":1},""00-0021206"":{""name"":""J.Street"",""att"":3}}}")
        Catch ex As System.Exception
            Throw ex
        End Try
        Return obj
End Function

我有时会得到以下异常（总是在同一行）：

title['name'] += 'x'

我将代码更改为更详细：

<class 'psycopg2.extras.DictRow'>
Traceback (most recent call last):
  File "rtk_film_nos.py", line 231, in <module>
    main()
  File "rtk_film_nos.py", line 150, in main
    title['name'] += 'x'
TypeError: list indices must be integers, not str

异常改为：

foo = title['name']
foo += 'x'
print type(title)
title['name'] = foo

如果我在try /中包装代码，除非它会很高兴地打印标题['name']的内容。

我不知道自己做错了什么。似乎由于某种原因python（v2.6.6）决定将dict视为列表，但我不知道为什么。

Answer 1

DictRow类是list的子类，until version 2.3.0您不能使用它来按名称分配元素。

您可以通过直接查找列索引来解决此问题：

title[title._index['name']] = foo

或者，对于增强的作业：

title[title._index['name']] += 'x'

Python认为psycopg2 DictRow是列表（至少它是什么样子）

1 个答案: