a=(a)
((a))
((a))
b=(b)
((b))
((b))

老师，这里面a和=、b和=之间需要空格吗，有什么要求？

老师，这个Android是安装不了软件？

老师，MySQL现在已经支持检查约束了吧，视频里还说不支持

闭包的特点是变量始终保存在内存中，这样随着闭包数量增加早晚会造成溢出的。所以闭包中的变量有约定俗成的释放原则么？然后是怎么释放的？

没问题了

老师 ，这个在Unicode下 CHAR(12)最多包含12字节信息，CHAR字段最多可以存储2000字节的信息，这个12B和2000B，都是CHAR类型的 他们的区别是什么？

底层的 这个键值 hash 存取过程没有听懂

C:\Windows\system32>workon django_env

(django_env) C:\Windows\System32>pip install mysqlclient

Collecting mysqlclient

  Using cached mysqlclient-1.4.6.tar.gz (85 kB)

Building wheels for collected packages: mysqlclient

  Building wheel for mysqlclient (setup.py) ... error

  ERROR: Command errored out with exit status 1:

   command: 'D:\python_env\django_env\Scripts\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\Jace\\AppData\\Local\\Temp\\pip-install-v7ymmrjl\\mysqlclient\\setup.py'"'"'; __file__='"'"'C:\\Users\\Jace\\AppData\\Local\\Temp\\pip-install-v7ymmrjl\\mysqlclient\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' bdist_wheel -d 'C:\Users\Jace\AppData\Local\Temp\pip-wheel-qh9stb47'

       cwd: C:\Users\Jace\AppData\Local\Temp\pip-install-v7ymmrjl\mysqlclient\

  Complete output (30 lines):

  running bdist_wheel

  running build

  running build_py

  creating build

  creating build\lib.win32-3.8

  creating build\lib.win32-3.8\MySQLdb

  copying MySQLdb\__init__.py -> build\lib.win32-3.8\MySQLdb

  copying MySQLdb\_exceptions.py -> build\lib.win32-3.8\MySQLdb

  copying MySQLdb\compat.py -> build\lib.win32-3.8\MySQLdb

  copying MySQLdb\connections.py -> build\lib.win32-3.8\MySQLdb

  copying MySQLdb\converters.py -> build\lib.win32-3.8\MySQLdb

  copying MySQLdb\cursors.py -> build\lib.win32-3.8\MySQLdb

  copying MySQLdb\release.py -> build\lib.win32-3.8\MySQLdb

  copying MySQLdb\times.py -> build\lib.win32-3.8\MySQLdb

  creating build\lib.win32-3.8\MySQLdb\constants

  copying MySQLdb\constants\__init__.py -> build\lib.win32-3.8\MySQLdb\constants

  copying MySQLdb\constants\CLIENT.py -> build\lib.win32-3.8\MySQLdb\constants

  copying MySQLdb\constants\CR.py -> build\lib.win32-3.8\MySQLdb\constants

  copying MySQLdb\constants\ER.py -> build\lib.win32-3.8\MySQLdb\constants

  copying MySQLdb\constants\FIELD_TYPE.py -> build\lib.win32-3.8\MySQLdb\constants

  copying MySQLdb\constants\FLAG.py -> build\lib.win32-3.8\MySQLdb\constants

  running build_ext

  building 'MySQLdb._mysql' extension

  creating build\temp.win32-3.8

  creating build\temp.win32-3.8\Release

  creating build\temp.win32-3.8\Release\MySQLdb

  C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\BIN\cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -Dversion_info=(1,4,6,'final',0) -D__version__=1.4.6 "-IC:\Program Files (x86)\MySQL\MySQL Connector C 6.1\include\mariadb" -ID:\python_env\django_env\include -Id:\python3.8.2\include -Id:\python3.8.2\include "-IC:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt" "-IC:\Program Files (x86)\Windows Kits\8.1\include\shared" "-IC:\Program Files (x86)\Windows Kits\8.1\include\um" "-IC:\Program Files (x86)\Windows Kits\8.1\include\winrt" /TcMySQLdb/_mysql.c /Fobuild\temp.win32-3.8\Release\MySQLdb/_mysql.obj /Zl /D_CRT_SECURE_NO_WARNINGS

  _mysql.c

  MySQLdb/_mysql.c(29): fatal error C1083: Cannot open include file: 'mysql.h': No such file or directory

  error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio 14.0\\VC\\BIN\\cl.exe' failed with exit status 2

  ----------------------------------------

  ERROR: Failed building wheel for mysqlclient

  Running setup.py clean for mysqlclient

Failed to build mysqlclient

Installing collected packages: mysqlclient

    Running setup.py install for mysqlclient ... error

    ERROR: Command errored out with exit status 1:

     command: 'D:\python_env\django_env\Scripts\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\Jace\\AppData\\Local\\Temp\\pip-install-v7ymmrjl\\mysqlclient\\setup.py'"'"'; __file__='"'"'C:\\Users\\Jace\\AppData\\Local\\Temp\\pip-install-v7ymmrjl\\mysqlclient\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\Jace\AppData\Local\Temp\pip-record-c_7pdi53\install-record.txt' --single-version-externally-managed --compile --install-headers 'D:\python_env\django_env\include\site\python3.8\mysqlclient'

         cwd: C:\Users\Jace\AppData\Local\Temp\pip-install-v7ymmrjl\mysqlclient\

    Complete output (30 lines):

    running install

    running build

    running build_py

    creating build

    creating build\lib.win32-3.8

    creating build\lib.win32-3.8\MySQLdb

    copying MySQLdb\__init__.py -> build\lib.win32-3.8\MySQLdb

    copying MySQLdb\_exceptions.py -> build\lib.win32-3.8\MySQLdb

    copying MySQLdb\compat.py -> build\lib.win32-3.8\MySQLdb

    copying MySQLdb\connections.py -> build\lib.win32-3.8\MySQLdb

    copying MySQLdb\converters.py -> build\lib.win32-3.8\MySQLdb

    copying MySQLdb\cursors.py -> build\lib.win32-3.8\MySQLdb

    copying MySQLdb\release.py -> build\lib.win32-3.8\MySQLdb

    copying MySQLdb\times.py -> build\lib.win32-3.8\MySQLdb

    creating build\lib.win32-3.8\MySQLdb\constants

    copying MySQLdb\constants\__init__.py -> build\lib.win32-3.8\MySQLdb\constants

    copying MySQLdb\constants\CLIENT.py -> build\lib.win32-3.8\MySQLdb\constants

    copying MySQLdb\constants\CR.py -> build\lib.win32-3.8\MySQLdb\constants

    copying MySQLdb\constants\ER.py -> build\lib.win32-3.8\MySQLdb\constants

    copying MySQLdb\constants\FIELD_TYPE.py -> build\lib.win32-3.8\MySQLdb\constants

    copying MySQLdb\constants\FLAG.py -> build\lib.win32-3.8\MySQLdb\constants

    running build_ext

    building 'MySQLdb._mysql' extension

    creating build\temp.win32-3.8

    creating build\temp.win32-3.8\Release

    creating build\temp.win32-3.8\Release\MySQLdb

    C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\BIN\cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -Dversion_info=(1,4,6,'final',0) -D__version__=1.4.6 "-IC:\Program Files (x86)\MySQL\MySQL Connector C 6.1\include\mariadb" -ID:\python_env\django_env\include -Id:\python3.8.2\include -Id:\python3.8.2\include "-IC:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt" "-IC:\Program Files (x86)\Windows Kits\8.1\include\shared" "-IC:\Program Files (x86)\Windows Kits\8.1\include\um" "-IC:\Program Files (x86)\Windows Kits\8.1\include\winrt" /TcMySQLdb/_mysql.c /Fobuild\temp.win32-3.8\Release\MySQLdb/_mysql.obj /Zl /D_CRT_SECURE_NO_WARNINGS

    _mysql.c

    MySQLdb/_mysql.c(29): fatal error C1083: Cannot open include file: 'mysql.h': No such file or directory

    error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio 14.0\\VC\\BIN\\cl.exe' failed with exit status 2

    ----------------------------------------

ERROR: Command errored out with exit status 1: 'D:\python_env\django_env\Scripts\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\Jace\\AppData\\Local\\Temp\\pip-install-v7ymmrjl\\mysqlclient\\setup.py'"'"'; __file__='"'"'C:\\Users\\Jace\\AppData\\Local\\Temp\\pip-install-v7ymmrjl\\mysqlclient\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\Jace\AppData\Local\Temp\pip-record-c_7pdi53\install-record.txt' --single-version-externally-managed --compile --install-headers 'D:\python_env\django_env\include\site\python3.8\mysqlclient' Check the logs for full command output.

安装mysqlclient报错

import random
from tkinter import *
from tkinter import messagebox
class Application(Frame):
    def __init__(self,master=None):
        super().__init__(master)
        self.master=master
        self.pack()
        self.createWidget()

    def createWidget(self):
        self.canvas=Canvas(self,width=300,height=400,bg="green") #创建组件
        self.canvas.pack()
        self.canvas.create_line(30,30,500,500) #画直线
        self.canvas.create_rectangle(20,50,80,40)
        global photo
        photo=PhotoImage(file=r"C:\Users\86137\Documents\mindplus-py\environment\Python3.6.5-64\tcl\tk8.6\images\logo64.gif")
        self.canvas.create_image(200,50,image=photo)

        Button(self,text="随机生成十个矩形",command=self.confirm).pack(side="left")

    def confirm(self):
        for x in range(0,10):
            x1 = random.randrange(int(self.canvas["width"]/2))
            y1 = random.randrange(int(self.canvas["height"] / 2))
            x2 = x1+random.randrange(int(self.canvas["width"] / 2))
            y2 = y1+random.randrange(int(self.canvas["height"] / 2))
            self.canvas.create_rectangle(x1,y1,x2,y2)


root=Tk()
root.geometry("500x600+300+300")
app=Application(master=root)
root.mainloop()

老师我这个为什么会报错？

Exception in Tkinter callback

Traceback (most recent call last):

  File "D:\python\lib\tkinter\__init__.py", line 1892, in __call__

    return self.func(*args)

  File "D:\python_exec\py02\GUI图形编程\canvas布图.py", line 24, in confirm

    x1 = random.randrange(int(self.canvas["width"]/2))

TypeError: unsupported operand type(s) for /: 'str' and 'int'

双击为什么打不开，任务管理器也不显示运行

一楼社长全的最后代码写错了吧，不是turtle.write=(distance),而是turtle.write(distance)

老师我赋值代码进去，右键没“run”，而且报了很多错误，是不是我的版本不对啊

老师，报这个错误是不是版本的问题啊？，我的MySQL 版本是8.0.18;   Django刚开始我装的是3.0.5的版本，
会报这个错误；然后我把Django降到和视频中的老师一样的版本（2.2.1版本），还是会报错；

[object Object]

都在图里了，如果可以   还需要什么操作

请问老师,是否是因为字符串在常量池中创建后找得都是常量池这个对象的地址,我自己试了下如果对象锁不是同一个常量值那么还是会并行的