添加键值对dict

Posted 2021-04-07

在以下代码中，我在'row [header]'处收到错误：

for field in Document._meta.get_fields():
    headers.append(field.name)

docs = Document.objects.order_by('id')
for doc in docs:
    row = {}
    for header in headers:
        if hasattr(doc, header):
            row[header] = getattr(doc, header)
    files.append(row)

Python说：TypeError：list indices必须是整数或切片，而不是str

出了什么问题？

Python回溯：

Traceback (most recent call last):
  File "/home/niels/PycharmProjects/sitesv/env/lib/python3.5/site-packages/django/core/handlers/exception.py", line 34, in inner
    response = get_response(request)
  File "/home/niels/PycharmProjects/sitesv/env/lib/python3.5/site-packages/django/core/handlers/base.py", line 126, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/home/niels/PycharmProjects/sitesv/env/lib/python3.5/site-packages/django/core/handlers/base.py", line 124, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/niels/PycharmProjects/sitesv/files/views.py", line 87, in get_file_list
    row[header] = getattr(doc, header)
TypeError: list indices must be integers or slices, not str

答案

答案通过评论确认：

变量row已经处于更高的范围，因此写入它会被另一个线程的写入覆盖。

将row的名称更改为其他内容会使问题消失。