Python's system programming--process

1. Debug (PDB)

Code:

 [[email protected] Gaoji]#   vim test2.py  1 #  !/usr/local/bin/python3  2 #  -*-coding:utf-8-*- 3 4 def   Getaverage (A, B):  5 result = a + b  6 print  ("  result=%d  " %result)  7 return   result  8 9 A = ten B = 2 XX C = a + b  ret = Getaverage (A, b)  print  (ret) 

[[email protected] Gaoji]#python3-m pdb test2.py>/home/weixin/gaoji/test2.py (4) <module>()-defGetaverage (A, b):(Pdb) L1#!/usr/local/bin/python32#-*-coding:utf-8-*-3 4defGetaverage (A, b):5 result = a +b6Print("result=%d"%result)7returnresult8 9 A = ten B = a + c = a +B (Pdb)

############################### #进程 ########################

Multi-tasking understanding:

######### #父进程与子进程的先后顺序理解 ################

[[email protected] process]#Vim 01-process. PY1#!/usr/local/bin/python32#-*-coding:utf-8-*-3 4ImportOS5Import Time6 ret =os.fork ()7 8ifRET = =0:9Print('---child process 1---') Ten Time.sleep (5) 11Print('---child process 2---') 12Else: 13Print('---parent process---') Time.sleep (3) 15 16Print('---over---')

Execution Result:

Summary: The value of RET has two, one is equal to 0, one is greater than 0; White point is executed two times.

################ #全局变量在多进程中不共享 ##############

[[email protected] process]#Vim 02-process. PY1#!/usr/local/bin/python32#-*-coding:utf-8-*-3 4 5ImportOs-6Import Time7 G_sum = 8 9 pid =os.fork ()10ifPID = =0:11Print('---process-01---') G_sum + = 1 13Print('---process-01--%d'%g_sum)14Else: Time.sleep (3) # # #为了保证让子进程优先运行16Print('---process-02---') 17Print('---process-02--%d'%g_sum)18

Execution Result:

[[email protected] process] #  ---process-01------process-01--101---process-02------process-02--100        # # #结果还是100, and did not become 101

Python's system programming--process