升级到Django2.2: AttributeError:模块'statistics‘没有属性'pstdev’

Question

当前设置：

Python 3.6

Django==2.2
gunicorn==19.1.0
coverage==4.4.1
django-suit==0.2.26
django-extensions==2.0.6
djangorestframework==3.8.2
djangorestframework-datatables==0.3.0
djangorestframework-csv==2.1.0
coreapi==2.3.3
Faker==0.9.0
pillow==5.2.0
simple-crypt==4.1.7
xlrd==1.1.0
django-crequest==2018.5.11
gitpython==2.1.11
django_icons==0.2.1

将Django从1.11升级到2.2。在清理了各种升级检查表中描述的一些明显的东西后，我被这个问题卡住了，这个问题似乎在任何地方都没有答案。迁移在一些“统计”模块上遇到了瓶颈。可能一些依赖模块与升级的Django不再兼容：

正在尝试：

> python manage.py runserver

获取：

File "/Users/myuser/.local/lib/python3.5/site-packages/django/db/backends/sqlite3/base.py", line 230, in get_new_connection
    conn.create_aggregate('STDDEV_POP', 1, list_aggregate(statistics.pstdev))
AttributeError: module 'statistics' has no attribute 'pstdev'

完整的回溯：

Exception in thread Thread-1:
Traceback (most recent call last):
  File "/Users/myuser/miniconda3/lib/python3.5/threading.py", line 914, in _bootstrap_inner
    self.run()
  File "/Users/myuser/miniconda3/lib/python3.5/threading.py", line 862, in run
    self._target(*self._args, **self._kwargs)
  File "/Users/myuser/.local/lib/python3.5/site-packages/django/utils/autoreload.py", line 54, in wrapper
    fn(*args, **kwargs)
  File "/Users/myuser/.local/lib/python3.5/site-packages/django/core/management/commands/runserver.py", line 120, in inner_run
    self.check_migrations()
  File "/Users/myuser/.local/lib/python3.5/site-packages/django/core/management/base.py", line 453, in check_migrations
    executor = MigrationExecutor(connections[DEFAULT_DB_ALIAS])
  File "/Users/myuser/.local/lib/python3.5/site-packages/django/db/migrations/executor.py", line 18, in __init__
    self.loader = MigrationLoader(self.connection)
  File "/Users/myuser/.local/lib/python3.5/site-packages/django/db/migrations/loader.py", line 49, in __init__
    self.build_graph()
  File "/Users/myuser/.local/lib/python3.5/site-packages/django/db/migrations/loader.py", line 212, in build_graph
    self.applied_migrations = recorder.applied_migrations()
  File "/Users/myuser/.local/lib/python3.5/site-packages/django/db/migrations/recorder.py", line 73, in applied_migrations
    if self.has_table():
  File "/Users/myuser/.local/lib/python3.5/site-packages/django/db/migrations/recorder.py", line 56, in has_table
    return self.Migration._meta.db_table in self.connection.introspection.table_names(self.connection.cursor())
  File "/Users/myuser/.local/lib/python3.5/site-packages/django/db/backends/base/base.py", line 256, in cursor
    return self._cursor()
  File "/Users/myuser/.local/lib/python3.5/site-packages/django/db/backends/base/base.py", line 233, in _cursor
    self.ensure_connection()
  File "/Users/myuser/.local/lib/python3.5/site-packages/django/db/backends/base/base.py", line 217, in ensure_connection
    self.connect()
  File "/Users/myuser/.local/lib/python3.5/site-packages/django/db/backends/base/base.py", line 195, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/Users/myuser/.local/lib/python3.5/site-packages/django/db/backends/sqlite3/base.py", line 230, in get_new_connection
    conn.create_aggregate('STDDEV_POP', 1, list_aggregate(statistics.pstdev))
AttributeError: module 'statistics' has no attribute 'pstdev'

谢谢你的建议。

Answer 1

您可能有一个自定义的statistics模块，它覆盖了标准库提供的模块。重命名自定义statistics模块以修复此问题。