old_contents: from __future__ import absolute_import
  from __future__ import print_function
  
  from typing import Any
  
  from argparse import ArgumentParser
  from django.core.management.base import BaseCommand
  from zerver.lib.actions import do_change_user_email
  from zerver.models import UserProfile, get_user_profile_by_email
  
  class Command(BaseCommand):
      help = """Change the email address for a user."""
  
      def add_arguments(self, parser):
          # type: (ArgumentParser) -> None
          parser.add_argument('old_email', metavar='<old email>', type=str,
                              help='email address to change')
          parser.add_argument('new_email', metavar='<new email>', type=str,
                              help='new email address')
  
      def handle(self, *args, **options):
          # type: (*Any, **str) -> None
          old_email = options['old_email']
          new_email = options['new_email']
          try:
              user_profile = get_user_profile_by_email(old_email)
          except UserProfile.DoesNotExist:
              print("Old e-mail doesn't exist in the system.")
              exit(1)
  
          do_change_user_email(user_profile, new_email)
  
new_contents: from __future__ import absolute_import
  from __future__ import print_function
  
  import sys
  
  from argparse import ArgumentParser
  from django.core.management.base import BaseCommand
  from typing import Any
  
  from zerver.lib.actions import do_change_user_email
  from zerver.models import UserProfile, get_user_for_mgmt
  
  class Command(BaseCommand):
      help = """Change the email address for a user."""
  
      def add_arguments(self, parser):
          # type: (ArgumentParser) -> None
          parser.add_argument('old_email', metavar='<old email>', type=str,
                              help='email address to change')
          parser.add_argument('new_email', metavar='<new email>', type=str,
                              help='new email address')
  
      def handle(self, *args, **options):
          # type: (*Any, **str) -> None
          old_email = options['old_email']
          new_email = options['new_email']
          try:
              user_profile = get_user_for_mgmt(old_email)
          except UserProfile.DoesNotExist:
              print("Old e-mail doesn't exist in the system.")
              sys.exit(1)
  
          do_change_user_email(user_profile, new_email)
  
subject: Use new get_user_for_mgmt function.