如何正确退出while循环？

Question

I have a program that runs through a list of names in 'serverlist.txt'. The user selects the database they want to search in by choosing option 1 or option 2. The program will run through all names in the list and provide the id tied to each name.

Name: Jupiter ID: 23 Name: Mars ID: 26 Name: Mercury ID: 27

This works fine but it doesn't stop. When the list is complete, it loops through everything all over again.

How do I stop it from going through the list more than once?

import pypyodbc
import os

def replaceid(connection, servername):
    try:
        cursor = connection.cursor()

        SQLCommand = ("SELECT Name, Location_ID "
            "FROM dbo.Server_ID "   # table name
            "with (nolock)"
            "WHERE Name = ?")
        Values = [servername]
        cursor.execute(SQLCommand,Values)
        results = cursor.fetchone()
        if results:

            print (" Name: " + results[0] + " ID: " + str(results[1]))
            print (" ")
            locationid(results, connection, servername)
        else:
            print (" ID for " + servername + " does not exist.")
            print (" ")
            connection.close()
    except:
        print("Database is down or you are not connected to network.")
        exit()

def start1():

    os.system('cls' if os.name == 'nt' else 'clear')
    array = []
    local = input('\n\n Type option 1 or 2: ')
    while True:
        with open("serverlist.txt", "r") as f:
            for servername in f:
                try:                

                    if local in ['1']:
                        connection = pypyodbc.connect('Driver={SQL Server};Server=db1;Database=WinOasis;Trusted_Connection=yes;')
                    elif local in ['2']:
                        connection = pypyodbc.connect('Driver={SQL Server};Server=db2;Database=WinOasis;Trusted_Connection=yes;')
                    else:
                        return
                except pypyodbc.Error as ex:
                    sqlstate = ex.args[0]
                    if sqlstate == '28000':
                        print ("You do not have access.")

                replaceid(connection, servername.strip())
    return

start1()

Answer 1

I think your return statement on the third to last line needs to be indented one level. Otherwise your while loop will run forever, because True will always be true!

Answer 2

You might want to add a break statement after you call replaceid(connection, servername.strip()) in start1()

You might also want a break statement after the exception clause ends.