How to specify custom date range in google adwords selector properly with python?

My goal is to get ACCOUNT_PERFORMANCE_REPORT with custom date range.

I've tried

oauth2_client = GoogleRefreshTokenClient(self.client_id, self.client_secret, refresh_token) adwords_client = AdWordsClient(developer_token, oauth2_client, self.user_agent) report_downloader = client.GetReportDownloader(version='v201809') report={   'reportName': 'Google xxx ACCOUNT_PERFORMANCE_REPORT',    'dateRangeType': 'CUSTOM_DATE',    'reportType': 'ACCOUNT_PERFORMANCE_REPORT',    'downloadFormat': 'CSV',    'selector':    {      'fields': ['CustomerDescriptiveName', 'Date', 'Cost'],       'dateRange': '20200501,20201031'   } } 

And got

Request Summary:  { 'clientCustomerId': 'None',  'includeZeroImpressions': 'True',  'server': 'adwords.google.com',  'skipColumnHeader': 'False',  'skipReportHeader': 'False',  'skipReportSummary': 'False',  'isError': True,  'errorMessage': '<?xml version="1.0" encoding="UTF-8" standalone="yes"?><reportDownload Error><ApiError><type>ReportDownloadError.INVALID_REPORT_DEFINITION_XML</type><trigger>Invalid ReportDefinition Xml: DateError.INVALID_STRING_DATE @ </t rigger><fieldPath></fieldPath></ApiError></reportDownloadError>' } 

but when i use

 report= {   'reportName': 'Google xxx ACCOUNT_PERFORMANCE_REPORT',    'dateRangeType': 'LAST_7_DAYS',    'reportType': 'ACCOUNT_PERFORMANCE_REPORT',    'downloadFormat': 'CSV',    'selector':    {      'fields': ['CustomerDescriptiveName', 'Date', 'Cost']   } } 

it's ok

The question is: How to specify custom dateRange range in selector properly?