With Python 3.7.9 and Django 3, the application always fails with the error “NameError: name ‘_mysql’ is not defined”.
We are doing some house cleaning to the project, disabling and enabling YUM repos, and removing and reinstalling packages. The issue happened when trying to restart the service after the change.
Please see the exception trace and pip package list attached in the Details section below, and let me know if you need to see the yum package information. We highly appreciate your help.
Details:
1. The full exception trace:
Exception in thread django-main-thread:
Traceback (most recent call last):
File "/data/app/venv3.7/lib/python3.7/site-packages/MySQLdb/__init__.py", line 18, in <module>
from . import _mysql
ImportError: libperconaserverclient.so.21: cannot open shared object file: No such file or directory
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/local/lib/python3.7/threading.py", line 926, in _bootstrap_inner
self.run()
File "/usr/local/lib/python3.7/threading.py", line 870, in run
self._target(*self._args, **self._kwargs)
File "/data/app/venv3.7/lib/python3.7/site-packages/django/utils/autoreload.py", line 53, in wrapper
fn(*args, **kwargs)
File "/data/app/venv3.7/lib/python3.7/site-packages/django/core/management/commands/runserver.py", line 110, in inner_run
autoreload.raise_last_exception()
File "/data/app/venv3.7/lib/python3.7/site-packages/django/utils/autoreload.py", line 76, in raise_last_exception
raise _exception[1]
File "/data/app/venv3.7/lib/python3.7/site-packages/django/core/management/__init__.py", line 357, in execute
autoreload.check_errors(django.setup)()
File "/data/app/venv3.7/lib/python3.7/site-packages/django/utils/autoreload.py", line 53, in wrapper
fn(*args, **kwargs)
File "/data/app/venv3.7/lib/python3.7/site-packages/django/__init__.py", line 24, in setup
apps.populate(settings.INSTALLED_APPS)
File "/data/app/venv3.7/lib/python3.7/site-packages/django/apps/registry.py", line 114, in populate
app_config.import_models()
File "/data/app/venv3.7/lib/python3.7/site-packages/django/apps/config.py", line 211, in import_models
self.models_module = import_module(models_module_name)
File "/usr/local/lib/python3.7/importlib/__init__.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
File "<frozen importlib._bootstrap>", line 983, in _find_and_load
File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 728, in exec_module
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "/data/app/venv3.7/lib/python3.7/site-packages/django/contrib/auth/models.py", line 2, in <module>
from django.contrib.auth.base_user import AbstractBaseUser, BaseUserManager
File "/data/app/venv3.7/lib/python3.7/site-packages/django/contrib/auth/base_user.py", line 48, in <module>
class AbstractBaseUser(models.Model):
File "/data/app/venv3.7/lib/python3.7/site-packages/django/db/models/base.py", line 122, in __new__
new_class.add_to_class('_meta', Options(meta, app_label))
File "/data/app/venv3.7/lib/python3.7/site-packages/django/db/models/base.py", line 326, in add_to_class
value.contribute_to_class(cls, name)
File "/data/app/venv3.7/lib/python3.7/site-packages/django/db/models/options.py", line 206, in contribute_to_class
self.db_table = truncate_name(self.db_table, connection.ops.max_name_length())
File "/data/app/venv3.7/lib/python3.7/site-packages/django/db/__init__.py", line 28, in __getattr__
return getattr(connections[DEFAULT_DB_ALIAS], item)
File "/data/app/venv3.7/lib/python3.7/site-packages/django/db/utils.py", line 214, in __getitem__
backend = load_backend(db['ENGINE'])
File "/data/app/venv3.7/lib/python3.7/site-packages/django/db/utils.py", line 111, in load_backend
return import_module('%s.base' % backend_name)
File "/usr/local/lib/python3.7/importlib/__init__.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "/data/app/venv3.7/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 15, in <module>
import MySQLdb as Database
File "/data/app/venv3.7/lib/python3.7/site-packages/MySQLdb/__init__.py", line 24, in <module>
version_info, _mysql.version_info, _mysql.__file__
NameError: name '_mysql' is not defined
2. The pip list:
amqp==5.0.2
anyjson==0.3.3
appdirs==1.4.4
arrow==0.13.2
asgiref==3.3.1
attrs==20.3.0
backcall==0.2.0
backports.functools-lru-cache==1.6.1
beautifulsoup4==4.9.3
billiard==3.6.3.0
caniusepython3==7.2.0
celery==5.0.4
certifi==2020.12.5
chardet==3.0.4
click==7.1.2
click-didyoumean==0.0.3
click-plugins==1.1.1
click-repl==0.1.6
decorator==4.4.2
distlib==0.3.1
Django==3.1.4
django-cors-headers==3.5.0
django-debug-toolbar==3.2
django-easy-pjax==1.3.0
django-rest-auth==0.9.5
djangorestframework==3.12.2
fake-factory==9999.9.9
fissix==20.8.0
gunicorn==20.0.4
idna==2.10
importlab==0.5.1
importlib-metadata==3.1.1
ipython==7.19.0
ipython-genutils==0.2.0
jedi==0.17.2
kombu==5.0.2
line-profiler==3.1.0
lxml==4.6.2
mock==4.0.2
modernize==0.8.0
mysqlclient==2.0.1
networkx==2.5
ninja==1.10.0.post2
packaging==20.7
parso==0.7.1
pexpect==4.8.0
pickleshare==0.7.5
Pillow==8.0.1
pip==21.0
pip-review==1.1.0
pipdeptree==1.0.0
prompt-toolkit==3.0.8
ptyprocess==0.6.0
Pygments==2.7.3
pyparsing==2.4.7
python-dateutil==2.8.1
pytype==2020.12.2
pytz==2020.4
PyYAML==5.3.1
qrcode==6.1
requests==2.25.0
setproctitle==1.2.1
setuptools==51.3.3
six==1.15.0
soupsieve==2.0.1
sqlparse==0.4.1
traitlets==5.0.5
typed-ast==1.4.1
urllib3==1.26.2
vine==5.0.0
wcwidth==0.2.5
wheel==0.36.2
yet-another-django-profiler==1.1.0
zipp==3.4.0