python、Django、djangorestframework升级遇到的坑（一）

具体环境升级介绍

python2.7升级到python3.6
Django1.8.11升级到Django 3.0
djangorestframework3.6.3升级到djangorestframework3.10.3
# 依赖包
pymysql==0.6.7
MarkupSafe==1.0
Mako==1.0.6
requests==2.18.1
celery==3.1.25
django-celery==3.2.2
six==1.11.0
httplib2==0.9.1
supervisor==4.1.0
suds==0.4

1.安装包

python3不支持的安装包：

suds

python3 需要多安装/替代的依赖包：

anyjson
suds-jurko

其余自动安装默认最新的
2.python2到python3语法/框架升级的坑
①抛出异常

# python2
try:
    pass
except ImportError, e:
	pass
	
# python3
try:
    pass
except ImportError as e:
	pass

②打开文件

# python2
with open("db_helper/script/get_running_state.sh", 'r') as f:
	system_status = f.read()
# python3
with open("db_helper/script/get_running_state.sh", 'rb') as f:
	system_status = f.read()

③打印

# python2
print 'xxxx'
# python3
print('xxx')

④内容导入路径

# python2
import models
# python3
from apps.system import models

⑤数据库表的改变

# 原有的
template = models.ForeignKey(TasksTemplates, verbose_name=u"所属巡检任务模板")
# 升级的
template = models.ForeignKey(TasksTemplates, verbose_name=u"所属巡检任务模板", on_delete=models.CASCADE)

⑥重新生成迁移文件
⑦utf-8的改变

# python2
reload(sys)
sys.setdefaultencoding('utf8')
# python3
不需要

⑧包导入的差异

# 原有的
from django.conf.urls import include
from rest_framework.decorators import list_route
from django.utils.six.moves.urllib.parse import urlparse
from urllib import quote
from django.core.servers.basehttp import FileWrapper
from rest_framework.compat import set_rollback
from HTMLParser import HTMLParser
# 升级的
from django.urls import include
from rest_framework.decorators import action
from urllib.parse import urlparse
from urllib.parse import quote
from wsgiref.util import FileWrapper
from rest_framework.views import set_rollback
from html.parser import HTMLParser
from functools import reduce
# 改变的
# urlpatterns列表/元组不再含有字符串
# url改为path或者re_path 样例：
urlpatterns = patterns(
    'sites.views',
    url(r'^$', 'index'),
    url(r'^healthz/$', 'healthz'),
)
urlpatterns = (
    re_path('^$', views.index),
    re_path('^healthz/$', views.healthz),
)
# 路由指向,使用views.+方法名
urlpatterns = patterns(
    'misc.views',
    url(r'^upload/$', 'upload'),
    url(r'^download/$', 'download'),
)
urlpatterns = (
    re_path(r'^upload/$', views.upload, name= 'upload'),
    re_path(r'^download/$', views.download, name= 'download'),
)

⑨版本升级包不存在

from django.utils.decorators import available_attrs
from django.conf.urls import patterns

⑩默认配置

# 低版本的
MIDDLEWARE_CLASSES
CORS_ORIGIN_WHITELIST = (
        'xxxx:443',
        'xxxx:8005',
    )
# 升级的
MIDDLEWARE
LANGUAGES = (
    ('en', 'English'),
    ('de', 'German'),
)
# Template加入
'django.contrib.messages.context_processors.messages'
CORS_ORIGIN_WHITELIST = (
        'http://xxxx:443',
        'http://xxxx:8005',
    )