Get information from one column in one sheet and match it to another column in another sheet, and extract it as a csv file.

Excel_Python.py

import xlrd
from csv import writer

def file_writing(client):
    #Function to write client details to a csv file (later to import into excel)
    with open("clients.csv", mode = "a") as file:
        csv_writer = writer(file)
        csv_writer.writerow(client)


def client_id_name():
  #replace this location with the path to your Excel document
    location = ("Path")
    work_book = xlrd.open_workbook(location)
    sheet1 = work_book.sheet_by_index(4)
    #print(sheet1.nrows)    
    #printing all columns
    for i in range(sheet1.nrows):
        #obtaining client id and saving it in a variable called client_id
        client_id = sheet1.cell_value(i,0)
        sheet2 = work_book.sheet_by_index(9)
        #obtaining client name from SMSC and comparing client id for similarity
        #Count Variable to keep count of details found or not
        count = 0
        for j in range(sheet2.nrows):
            table2_id = sheet2.cell_value(j,1)
            #Obtaining client Name
            if client_id == table2_id:
                client_name = sheet2.cell_value(j,2)
                print(f"{client_id} {client_name}")
                count = 1
                #passing client name to csv
                file_writing(client_name)
                #break
            elif (sheet2.nrows - j) == 1 and client_id != table2_id and count == 0:
              #Catching Cells with no equivalent in the other Sheet
                print(f"Error!!!{client_id}")
                #passing client name to csv
                client_name = "NONE FOUND"
                file_writing(client_name)
    
client_id_name()