首页 \ 问答 \ 使用.apply（）来比较元素(use of .apply() for comparing elements)

使用.apply（）来比较元素(use of .apply() for comparing elements)

 我有一个有数千个项目的数据框 ，其中列“ 组 ”的值重复两到十次。 该数据框有七列，其中之一被命名为“ url ”; 另一个“ 旗帜 ”。 所有这些都是字符串。  
 我想用熊猫来遍历这些群体。 对于每个组，我希望在“ url ”列中找到最长的项目，并在与该项目对应的“ 标志 ”列中存储“0”或“1”。 我尝试了以下方法，但无法使其工作。 我想1）摆脱下面的循环，2）能够通过df.apply（...）比较组中的所有项目  
 all_groups = df["group"].drop_duplicates.tolist()

 for item in all_groups:

     df[df["group"]==item].apply(lambda x: Here I would like to compare the items within one group)
 
 可以应用（）和lambda在这种情况下使用？ 任何更快的方式来实现这一点？  
 谢谢！ 

I have a dataframe df of thousands of items where the value of the column "group" repeats from two to ten times. The dataframe has seven columns, one of them is named "url"; another one "flag". All of them are strings.  
I would like to use Pandas in order to traverse through these groups. For each group I would like to find the longest item in the "url" column and store a "0" or "1" in the "flag" column that corresponds to that item. I have tried the following but I can not make it work. I would like to 1) get rid of the loop below, and 2) be able to compare all items in the group through df.apply(...) 
 all_groups = df["group"].drop_duplicates.tolist()

 for item in all_groups:

     df[df["group"]==item].apply(lambda x: Here I would like to compare the items within one group)
 
Can apply() and lambda be used in this context? Any faster way to implement this? 
Thank you!

原文：https://stackoverflow.com/questions/45578600

更新时间：2022-02-03 20:02

最满意答案

 试试这个：  
Sub matrix()
Dim arr() As Variant
Dim totrow As Long
Dim j As Long
Dim t As Long
Dim p As Long
Dim x As Long
Dim ws As Worksheet
Set ws = Sheets("Sheet1")
'Set your array of numbers
arr = Array(2, 3, 4)
'If you want to refer to ranges on Sheet1 use:
'arr = Array(ws.Range("T1"), ws.Range("U1"), ws.Range("V1"))

totrow = 1
For j = LBound(arr) To UBound(arr)
    totrow = totrow * arr(j)
    x = x + arr(j)
Next j
ws.Range(ws.Cells(1, 1), ws.Cells(totrow, x)).Value = 0
p = 1

For j = UBound(arr) To LBound(arr) Step -1
    For t = 1 To totrow Step 1
        For i = 1 To arr(j)
            ws.Range(ws.Cells(t, x - arr(j) + i), ws.Cells(t + p - 1, x - arr(j) + i)).Value = 1
            t = t + p
        Next i
        t = t - 1
    Next t
    p = p * arr(j)
    x = x - arr(j)
Next j
End Sub
 
 这适用于数组中的任何值或数组中的任意数量的整数。 主要限制是工作表上的行数和列数。 

Try this: 
Sub matrix()
Dim arr() As Variant
Dim totrow As Long
Dim j As Long
Dim t As Long
Dim p As Long
Dim x As Long
Dim ws As Worksheet
Set ws = Sheets("Sheet1")
'Set your array of numbers
arr = Array(2, 3, 4)
'If you want to refer to ranges on Sheet1 use:
'arr = Array(ws.Range("T1"), ws.Range("U1"), ws.Range("V1"))

totrow = 1
For j = LBound(arr) To UBound(arr)
    totrow = totrow * arr(j)
    x = x + arr(j)
Next j
ws.Range(ws.Cells(1, 1), ws.Cells(totrow, x)).Value = 0
p = 1

For j = UBound(arr) To LBound(arr) Step -1
    For t = 1 To totrow Step 1
        For i = 1 To arr(j)
            ws.Range(ws.Cells(t, x - arr(j) + i), ws.Cells(t + p - 1, x - arr(j) + i)).Value = 1
            t = t + p
        Next i
        t = t - 1
    Next t
    p = p * arr(j)
    x = x - arr(j)
Next j
End Sub
 
This will work for any value in the array or any number of integers in the array. The main limitation is the number of rows and columns on the sheet.

使用.apply（）来比较元素(use of .apply() for comparing elements)

最满意答案

相关问答

动态为VBA中的循环(Dynamic For Loops in VBA)[2023-05-09]

VBA中的双循环(Dual Loops in VBA)[2023-02-24]

VBA数组和循环(VBA Arrays and Loops)[2023-10-18]

VBA用循环转置数据(VBA Transpose data with loops)[2023-02-16]

EXCEL VBA：暂停'For Loops'(EXCEL VBA: Suspended 'For Loops')[2023-02-10]

VBA DO循环问题(VBA DO Loops Issue)[2023-11-21]

使用2“For Each”循环 - Word VBA(Use 2 “For Each” Loops Together - Word VBA)[2023-10-21]

VBA中的高效循环(Efficient Loops in VBA)[2020-01-27]

VBA嵌套循环提前退出(VBA nested loops exiting early)[2022-04-05]

表和循环VBA(Tables and loops VBA)[2024-02-24]

相关文章

最新问答