[terry笔记]文件操作

如下记录一次作业：

很显然，我这个应该属于二逼青年版，会在以后更新文艺青年版的答案。

1、模仿sed，一个文件中，用新字符串替换老字符串。

 # file = input("file_name")
 # old_str = input("old_str")
 # new_str = input("new_str")
 def change_str(file, old_str, new_str):
     f = open(file, 'r')
     lines = f.readlines()
     flen = len(lines)
     for i in range(flen):
         if old_str in lines[i]:
             lines[i] = lines[i].replace(old_str, new_str)
     open(file, 'w').writelines(lines)
     f.close()

 change_str('aaa', 'A', 'ttttttttttttttttttttttttt')

2、查找、添加、删除特定的内容

 file=open("haproxy_conf","r")
 rl=file.readlines()
 lens=len(rl)
 for i in range(lens):
     if "oldboy.org" and "frontend" in rl[i]:
         if rl[i-1] is "\n":
             print(rl[i].strip())
             while True:
                 i += 1
                 print(rl[i].strip())
                 if i == lens-1:
                     break

 arg = {
     'bakend': 'www.oldboy.org',
     'record': {
         'server': '100.1.7.9',
         'weight': 20,
         'maxconn': 30
     }
 }
 arg_list=[]
 file=open("haproxy_conf","r+")
 lines=file.readlines()
 print(lines)
 for i in arg:
     if "bakend" == i:
         arg_list.insert(0,i)
         arg_list.insert(1,arg[i])
     elif "record" == i:
         arg_list.append(i)
         for key,value in arg[i].items():
             if key == "server":
                 arg_list.insert(3,key)
                 arg_list.insert(4,value)
         for key, value in arg[i].items():
             if key == "weight":
                 arg_list.insert(5,key)
                 arg_list.insert(6,value)
         for key, value in arg[i].items():
             if key == "maxconn":
                 arg_list.insert(7,key)
                 arg_list.insert(8,value)
 arg_list[0]=arg_list[0]+" "+arg_list[1]+"\n"
 arg_list.remove(arg_list[1])
 arg_list[5]=str(arg_list[5])
 arg_list[7]=str(arg_list[7])
 arg_list[1]="\t"+arg_list[1]+" "+arg_list[2]+" "+arg_list[3]+" "+arg_list[4]+" "+arg_list[5]+" "+arg_list[6]+" "+arg_list[7]
 for m in range(6):
     n = 2
     arg_list.remove(arg_list[n])
 lines.append("\n")
 lines.append("\n")
 print(lines)
 lines = lines +arg_list
 print(lines)
 file.writelines(lines)
 file.close()