需求：

現有一個 csv檔案，包含'CNUM'和'COMPANY'兩列，資料裡包含空行，且有內容重複的行資料。

要求：

1）去掉空行；
2）重複行資料只保留一行有效資料；
3）修改'COMPANY'列的名稱為'Company_New‘；
4）並在其後增加六列，分別為'C_col',‘D_col',‘E_col',‘F_col',‘G_col',‘H_col'。

一，使用 Python Pandas來處理：

import pandas as pd
import numpy as np
from pandas import DataFrame,Series

def deal_with_data(filepath,newpath):
  file_obj=open(filepath)
  df=pd.read_csv(file_obj)  # 讀取csv檔案，建立 DataFrame
  df=df.reindex(columns=['CNUM','COMPANY','C_col','D_col','E_col','F_col','G_col','H_col'],fill_value=None)  # 重新指定列索引
  df.rename(columns={'COMPANY':'Company_New'},inplace = True) # 修改列名
  df=df.dropna(axis=0,how='all')         # 去除 NAN 即檔案中的空行
  df['CNUM'] = df['CNUM'].astype('int32')    # 將 CNUM 列的資料型別指定為 int32
  df = df.drop_duplicates(subset=['CNUM','Company_New'],keep='first') # 去除重複行
  df.to_csv(newpath,index=False,encoding='GBK')
  file_obj.close()
  
if __name__=='__main__':
  file_path=r'C:\Users\12078\Desktop\python\CNUM_COMPANY.csv'
  file_save_path=r'C:\Users\12078\Desktop\python\CNUM_COMPANY_OUTPUT.csv'
  deal_with_data(file_path,file_save_path)

二，使用 VBA來處理：

Option Base 1
Option Explicit

Sub main()
 On Error GoTo error_handling
 Dim wb         As Workbook
 Dim wb_out       As Workbook
 Dim sht         As Worksheet
 Dim sht_out       As Worksheet
 Dim rng         As Range
 Dim usedrows      As Byte
 Dim usedrows_out    As Byte
 Dim dict_cnum_company  As Object
 Dim str_file_path    As String
    Dim str_new_file_path  As String
    'assign values to variables:
    str_file_path = "C:\Users\12078\Desktop\Python\CNUM_COMPANY.csv"
    str_new_file_path = "C:\Users\12078\Desktop\Python\CNUM_COMPANY_OUTPUT.csv"
 
 Set wb = checkAndAttachWorkbook(str_file_path)
 Set sht = wb.Worksheets("CNUM_COMPANY")
 Set wb_out = Workbooks.Add
 wb_out.SaveAs str_new_file_path,xlCSV 'create a csv file
 Set sht_out = wb_out.Worksheets("CNUM_COMPANY_OUTPUT")

 Set dict_cnum_company = CreateObject("Scripting.Dictionary")
 usedrows = WorksheetFunction.Max(getLastValidRow(sht,"A"),getLastValidRow(sht,"B"))

 'rename the header 'COMPANY' to 'Company_New',remove blank & duplicate lines/rows.
 Dim cnum_company As String
 cnum_company = ""
 For Each rng In sht.Range("A1","A" & usedrows)
   If VBA.Trim(rng.Offset(0,1).Value) = "COMPANY" Then
     rng.Offset(0,1).Value = "Company_New"
   End If
   cnum_company = rng.Value & "-" & rng.Offset(0,1).Value
   If VBA.Trim(cnum_company) <> "-" And Not dict_cnum_company.Exists(rng.Value & "-" & rng.Offset(0,1).Value) Then
     dict_cnum_company.Add rng.Value & "-" & rng.Offset(0,1).Value,""
   End If
 Next rng
 
 'loop the keys of dict split the keyes by '-' into cnum array and company array.
 Dim index_dict As Byte
 Dim arr_cnum()
 Dim arr_Company()
 For index_dict = 0 To UBound(dict_cnum_company.keys)
   ReDim Preserve arr_cnum(1 To UBound(dict_cnum_company.keys) + 1)
   ReDim Preserve arr_Company(1 To UBound(dict_cnum_company.keys) + 1)
   arr_cnum(index_dict + 1) = Split(dict_cnum_company.keys()(index_dict),"-")(0)
   arr_Company(index_dict + 1) = Split(dict_cnum_company.keys()(index_dict),"-")(1)
   Debug.Print index_dict
 Next

 'assigns the value of the arrays to the celles.
 sht_out.Range("A1","A" & UBound(arr_cnum)) = Application.WorksheetFunction.Transpose(arr_cnum)
 sht_out.Range("B1","B" & UBound(arr_Company)) = Application.WorksheetFunction.Transpose(arr_Company)

 'add 6 columns to output csv file:
 Dim arr_columns() As Variant
 arr_columns = Array("C_col","D_col","E_col","F_col","G_col","H_col")  '
 sht_out.Range("C1:H1") = arr_columns
 Call checkAndCloseWorkbook(str_file_path,False)
 Call checkAndCloseWorkbook(str_new_file_path,True)

Exit Sub
error_handling:
  Call checkAndCloseWorkbook(str_file_path,False)
  Call checkAndCloseWorkbook(str_new_file_path,False)
End Sub

' 輔助函式：
'Get last row of Column N in a Worksheet
Function getLastValidRow(in_ws As Worksheet,in_col As String)
  getLastValidRow = in_ws.Cells(in_ws.Rows.count,in_col).End(xlUp).Row
End Function

Function checkAndAttachWorkbook(in_wb_path As String) As Workbook
  Dim wb As Workbook
  Dim mywb As String
  mywb = in_wb_path
  
  For Each wb In Workbooks
    If LCase(wb.FullName) = LCase(mywb) Then
      Set checkAndAttachWorkbook = wb
      Exit Function
    End If
  Next
  
  Set wb = Workbooks.Open(in_wb_path,UpdateLinks:=0)
  Set checkAndAttachWorkbook = wb

End Function
 
Function checkAndCloseWorkbook(in_wb_path As String,in_saved As Boolean)
  Dim wb As Workbook
  Dim mywb As String
  mywb = in_wb_path
  For Each wb In Workbooks
    If LCase(wb.FullName) = LCase(mywb) Then
      wb.Close savechanges:=in_saved
      Exit Function
    End If
  Next
End Function

三，輸出結果：

兩種方法輸出結果相同：

四，比較總結：

Python pandas 內建了大量處理資料的方法，我們不需要重複造輪子，用起來很方便，程式碼簡潔的多。
Excel VBA 處理這個需求，使用了 陣列，字典等資料結構（實際需求中，資料量往往很大，所以一些地方沒有直接使用遍歷單元格的方法），以及處理字串，陣列和字典的很多方法，對檔案的操作也很複雜，一旦出錯，除錯起來比python也較困難，程式碼已經儘量優化，但還是遠比 Python要多。

到此這篇關於VBA處理資料與Python Pandas處理資料案例比較分析的文章就介紹到這了,更多相關VBA與Python Pandas處理資料內容請搜尋我們以前的文章或繼續瀏覽下面的相關文章希望大家以後多多支援我們！