Question

是否有任何内置方法来打印python列表中存在的重复元素。

我可以编写相同的程序。

我要搜索的只是是否有任何内置方法或相同的东西。

例如：

对于输入[4,3,2,4,5,6,4,7,6,8]

我需要操作4,6

Answer 1

collections中有一个Counter类可以解决问题

from collections import Counter


lst = [4,3,2,4,5,6,4,7,6,8]
d =  Counter(lst)  # -> Counter({4: 3, 6: 2, 3: 1, 2: 1, 5: 1, 7: 1, 8: 1})
res = [k for k, v in d.items() if v > 1]
print(res)
# [4, 6]

Answer 2

可能相关的重复问题：How do I find the duplicates in a list and create another list with them?

简单答案：

>>> l = [1,2,3,4,4,5,5,6,1]
>>> set([x for x in l if l.count(x) > 1])
set([1, 4, 5])

Answer 3

通过简单的内置功能，您可以执行以下操作：

Protected Sub createTable()
    Try

        Dim listB As New ArrayList()
        Dim dt As New DataTable
        Dim info As SessioneUtente = Session(SessionVariables.InformazioniUtente)
        Dim id As String = info.getIdDisciplinaDefault.ToString
        dt = operations.G_Number(id)

        If dt.Rows.Count = 0 Then
            notifica.Text = "There is no number for this id"

        Else

            For Each row In dt.Rows
                list.Add(row(0))
                listB.Add(row(0))
            Next
            listB.Add(23)
            listB.Add(24)
            listB.Add(25)

            Dim cell1 As New TableCell
            Dim cell2 As New TableCell
            Dim Nr As New Label
            Dim Icon As New Label
            Dim row1 As New TableRow
            Dim row2 As New TableRow
            For Each item In listB
                If list.Contains(item) Then    
                    Nr.Text = item
                   Icon.Text = "<img = src='../Images/Icon1.png' />"
                    cell1.Controls.Add(Nr)
                    cell2.Controls.Add(Icon)
                    row1.Cells.Add(cell1)
                    row2.Cells.Add(cell2)
                Else
                   Nr.Text = item & vbLf
                    Icon.Text = "<img = src='../Images/Icon2.png' />"
                    cell1.Controls.Add(Nr)
                    cell2.Controls.Add(Icon)
                    row1.Cells.Add(cell1)
                    row2.Cells.Add(cell2)
                End If

            Next
            tabel.Rows.Add(row1)
            tabel.Rows.Add(row2)
            notifica.Visible = False

        End If

    Catch ex As Exception
        Dim log As New Log
        log.writeLog("default", ex)
    End Try
End Sub

Answer 4

这是一个简单的演示

    x = [1,2,3,5,3,2]
    y = []
    for a in x:
        if not a in y:
            y.append(a)
    print(a)

这就是它的工作方式。对x中的每个项目进行迭代。如果y中当前的迭代项目不存在，请添加

如何仅打印python列表中的重复元素

4 个答案: