Lesson 9th: Backing up MySQL databases, overriding parent classes, unittest frames, multithreading

1. Write code to back up the MySQL database:

1) under Linux, back up the MySQL database and execute the command under the shell:mysqldump-uroot-p123456-a >db_bak.sql

Import Osimport Datetimeclass bakdb (object): Def __init__ (self, IP, username, passwd, port=3306, path= '/tmp/db_bak '): Self.ip = IP Self.username = Username self.passwd = passwd Self.port = Port Self.path = Path def check_path_exist (self): If not Os.path.isdir (Self.path): Os.mkdir (Self.path) def bak_db (s ELF): # mysqldump-u%s-p%s-h%s-a > **.sql filename = str (datetime.date.today ()) + '. sql ' SELF.C Heck_path_exist () Abs_file = Os.path.join (Self.path, filename) # becomes absolute path command = ' Mysqldump-u{u Sername}-p{passwd}-p{port}-h{ip}-A > {filename} '. Format (Username=self.username, passwd= SELF.PASSWD, Port=self.port, Ip=self.ip, Filename=abs_file) p Rint (command) os.system print ("Database backup complete") obj = bakdb (' **.**.**.** ', ' user ', ' passwd ') obj.bak_db ()

2. Overriding methods of the parent class

3. Unit Test-unittest Framework:

Import unittest Import Htmltestrunner                                                                                                                                                                         From Beautifulreport import Beautifulreport                                                                                                                                    Def calc (x, y): return x + y Class Testcalc (UnitTest.                                                                 TestCase): def setUp (self):                                                                                                                                 Print (' I am setup ')     def test_pass_case (self): "This is the test case passed" res = Calc (1, 2) Self                                                                                                                              . assertequal (3, RES)                                                             def test_fail_case (self): "This is a failed test case"                                                             res = Calc (9, 8)                                                                                                                             Self.assertequal (98, RES)                                                                def test_a (self):                                                               "This is an ordinary test case" pass                                                                                   def test_haha (self):                                                                                                                                       "This is hahaha test case"                                                              def tearDown (self):                                                                                                                                   Print (' I am teardown ')                                                                 @classmethod                                                               def setupclass (CLS): # Run one time before all use cases are executed                                                                                                                                 Print (' I am setupclass ')                                                          @classmethod       def teardownclass (CLS): # Run Once after all the use cases have completed                                                                                                                                                                                 Print (' I am teardownclass ') if __name__ = = ' __main__ ': Unittest.main () #                                                                                                                  All test cases in the current Python file are run # suite = UnitTest. TestSuite () # defines a test suite # suite.addtest (Testcalc (' Test_pass_case ')) # addtest parameter is TestCase Instance or Testsu # suite.addtest (Testcalc (' Test_fail_case ')) # suite.addtest (Testcalc (' Test_a                                                                                                   ') # Single add test case        # suite.addtests (Unittest.makesuite (Testcalc)) # addtests parameters are made up of test cases or test suites # f = open (' report.html ', ' WB ') # Run                                                                                                                                       NER = Htmltestrunner.htmltestrunner (stream=f,title= ' Test Report ', Descriptio # Runner.run (Suite) # Beautifulreport Bag                                            Ability to generate better-looking test reports for the interface # result = Beautifulreport (suite)  # Result.report (filename= ' reportb.html ', description= ' Test report ', log_path= '. ')

　　2) There is also a way to write all cases in a directory, and then write a code that runs all case:

Import unittestfrom beautifulreport Import beautifulreportimport xmlrunner   # pip Inttall xmlrunnersuite = unittest. TestSuite () # Testloader is used to load testcase to TestSuite all_case = unittest.defaultTestLoader.discover (' cases ', ' test*.py '  # The first parameter is the directory, and the second argument is the use case file with test, which starts with the all_case: the type of the    suite.addtests. # cases  is <class ' Unittest.suite.TestSuite ' >print (Suite) # list Generation # [Suite.addtests (case)-case in All_case]result = Beautifulreport ( Suite) Result.report (filename= ' report_all_case.html ', description= ' Test report ', log_path= '. ') # runner = Xmlrunner. Xmltestrunner ('. ')  # Generate Report # Runner.run (Suite)  # Running Use cases in the current directory in order to produce XML-formatted reports to Jenkins

Test_buy.pyimport unittestclass testbuy (unittest. TestCase):    def test_a (self):        self.assertequal (1, 1)    def test_b (self):        self.assertequal (1, 2)

4. Multithreading:

1) The program we open is a process with at least one thread in the process

2) The thread is contained in the process, the thread is the smallest execution unit, and the threads are independent of each other

3) After the main thread from N child threads, continue execution until the end, the child threads may still be executing, the sub-thread working time is not counted,

      So tell the main thread to wait until the sub-thread finishes executing before ending the program

import threadingimport timeimport requestsdef sayHi (name): Time.sleep (2) Prin T (name) def downhtml (URL, name): Content = Requests.get (URL). Content f = open (name, ' WB ') f.write (content) f.cl OSE () urls = [[' Nnzhp ', ' http://www.nnzhp.cn '], [' dsx ', ' http://www.imdsx.cn '], [' besttest ', ' http://www.besttest . cn ']]# single thread run # start_time = Time.time () # for URLs in urls:# downhtml (url[1], url[0]) # end_time = Time.time () # Print (end _time-start_time) # multithreaded Run start_time = Time.time () threads = []for URL in urls:t = threading. Thread (target=downhtml, args= (url[1], url[0]) # starts a thread T.start () # runs # waits for a child thread to finish working # T.join () # After the main thread has started a child thread, wait for the child The thread runs at the end; the next cycle is a new thread threads.append (t) for T in Threads: # The main thread has been looping through 3 sub-threads until they are all done Alive T.join () # main thread waiting for child thread end_time = Ti Me.time () print (end_time-start_time) # for I in range: # t = Threading. Thread (Target=sayhi, args= (' Little Black ')) # Start a thread, here the small black behind to add a comma # T.start () # Run 

　　4) Multi-process module

Import Multiprocessingimport Timedef Run ():    time.sleep (2)    print ("Multi-process") for    I in range (5):        p = Multiprocessing. Process (target=run2)        P.start () def run2 ():    print ("Multi-process Start") if __name__ = = ' __main__ ': for    I in range (5):        p = multiprocessing. Process (Target=run)        P.start ()

5) Daemon Process

Import Threadingimport timedef pz ():    time.sleep (2)    print (' valet ')    threads = []for i in range:    t = Threading. Thread (TARGET=PZ)    T.setdaemon (True)  # Sets the child thread as the daemon thread, daemon: Once the main thread ends immediately, the child thread ends immediately, regardless of whether the child thread has run out,    T.start ()    Threads.append (t) # for T in threads:#     t.join ()  # If the thread calls T.join (), the daemon does not work time.sleep (3) print (' Done '   # without T.join (), print done first, then print 50 valet

　 6) Thread Lock

Import threadingfrom Threading Import Locknum = 0lock = Lock ()  # Apply for a lock def run ():    Global num    lock.acquire () 
   # locking    num + = 1    lock.release ()  # unlock lis = []for i in Range (5):    t = Threading. Thread (Target=run)    T.start ()    lis.append (t) for T in Lis:    t.join () print (' over ', num) # Lock-in to prevent simultaneous modification of data at multiple threads may result in incorrect data. # It doesn't matter if you don't lock the Python3,

Lesson 9th: Backing up MySQL databases, overriding parent classes, unittest frames, multithreading