如何修复在导入包含其中一个字段的 excel 时提高值错误( "Unknown string format:" ， 时间线) 为空

Question

django openpyxl 为空时的日期字段错误

我想导入 excel 工作表，但日期字段为空。

class Drgmt(models.Model):
      date_ori = models.DateTimeField(default=None, null=True, blank=True)

def import(request):
    #Many lines before
    date_ori = dt.datetime.strftime(parse(row_data[19]), '%Y-%m-%d %H:%M:%S')
    #Many lines after

回溯(最近一次调用(：

  File "C:UsersAppDataRoamingPythonPython37site-packagesdjangocorehandlersexception.py", l
ine 34, in inner
    response = get_response(request)
  File "C:UsersAppDataRoamingPythonPython37site-packagesdjangocorehandlersbase.py", line 1
15, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "C:UsersAppDataRoamingPythonPython37site-packagesdjangocorehandlersbase.py", line 1
13, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "C:UsersDesktopperformancecuivreviews.py", line 57, in importeradsl date_ori = dt.datetime.strftime(parse(row_data[19]), '%Y-%m-%d %H:%M:%S')
File "C:UsersAppDataLocalContinuumanaconda3libsite-packagesdateutilparser_parser.py", li
ne 1356, in parse
    return DEFAULTPARSER.parse(timestr, **kwargs)
  File "C:UsersAppDataLocalContinuumanaconda3libsite-packagesdateutilparser_parser.py", li
ne 648, in parse
    raise ValueError("Unknown string format:", timestr)
ValueError: ('Unknown string format:', 'None')
[18/Jun/2019 08:37:02] "POST /cuivre/ HTTP/1.1" 500 85133

Answer 1

好吧，错误消息相当清楚：您将字符串'None'作为dateutil.parser.parse()的timestr参数传递，而解析器显然无法将其解析为日期。

解决方案也很明显：处理异常：

def import(request):
    #Many lines before
    try:
        date_ori = parse(row_data[19])
    except ValueError as e:
        # what you want to do here depends on your app's specs and rules...
        # you could return an error response, or skip the row and
        # just display a warning, etc etc
        do_something_with_the_exception_here()
    else:
        date_ori = dt.datetime.strftime(date_ori, '%Y-%m-%d %H:%M:%S')
    #Many lines after