Python函数的设计规范
1、Python函数设计时具备耦合性和聚合性
1)、耦合性:
(1).尽可能通过参数接受输入,以及通过return产生输出以保证函数的独立性;
(2).尽量减少使用全局变量进行函数间通信;
(3).不要在函数中直接修改可变类型的参数;
(4).避免直接改变定义在另外一个模块中的变量;
2)、聚合性:
(1).每个函数都应该有一个单一的、目的统一的目标;
(2).每个函数的功能都应该相对简单;
2、Python函数在脚本中应用示例
例1: 将/etc/passwd文件中的每一行都分隔为一个列表
[root@test0528]# vim test1.py #!/usr/bin/python27 # importre filename ='/etc/passwd' f1 =open(filename,'r') l1 =f1.readlines() bash =[] for i inl1: bash.append(i) defgenList(x): y = 0 x = len(bash) while y <= x: yield bash[y] y += 1 g1 =genList(bash) count =0 whilecount < len(bash): gg=g1.next() linelist = gg.split(':') print linelist count += 1 f1.close() [root@test0528]# ./test1.py ['root','x', '0', '0', 'root', '/root', '/bin/bash\n'] ['bin','x', '1', '1', 'bin', '/bin', '/sbin/nologin\n'] ['daemon','x', '2', '2', 'daemon', '/sbin', '/sbin/nologin\n'] ...... ['nginx','x', '496', '493', 'nginx user', '/var/cache/nginx','/sbin/nologin\n'] ['mysql','x', '27', '27', 'MySQL Server', '/var/lib/mysql','/bin/bash\n'] ['redis','x', '495', '492', 'Redis Database Server', '/var/lib/redis','/sbin/nologin\n']
例2: 将任意文件按用户指定的分隔符把每一行都分隔为一个列表
[root@test0528]# vim test2.py #!/usr/bin/python27 # importre #print"PLease input filename:" #filename= raw_input() filename =str(raw_input("PLease input filename: ")) f1 =open(filename,'r') l1 =f1.readlines() #print"PLease input separator:" #separator= raw_input() separator= str(raw_input("PLease input separator: ")) bash =[] for i inl1: bash.append(i) defgenList(x): y = 0 x = len(bash) while y <= x: yield bash[y] y += 1 g1 =genList(bash) count =0 whilecount < len(bash): gg=g1.next() linelist = gg.split(separator) print linelist count += 1 f1.close() [root@test0528]# ./test2.py PLeaseinput filename: /etc/passwd PLeaseinput separator: : ['root','x', '0', '0', 'root', '/root', '/bin/bash\n'] ['bin','x', '1', '1', 'bin', '/bin', '/sbin/nologin\n'] ['daemon','x', '2', '2', 'daemon', '/sbin', '/sbin/nologin\n'] ... ['nginx','x', '496', '493', 'nginx user', '/var/cache/nginx','/sbin/nologin\n'] ['mysql','x', '27', '27', 'MySQL Server', '/var/lib/mysql','/bin/bash\n'] ['redis','x', '495', '492', 'Redis Database Server', '/var/lib/redis','/sbin/nologin\n'] 例3:用折叠的方式(reduce)求阶乘 [root@test0528]# vim test3.py #!/usr/bin/python27 # getn! num =int(raw_input('please nput a number:')) num +=1 list =range(1,num) deffunc(m,n): return m*n x =reduce(func,list) printx [root@test0528]# ./test3.py pleasenput a number:4 24
以上这篇对Python函数设计规范详解就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持脚本之家。