利用切片操作,实现一个trim()函数,去除字符串首尾的空格,注意不要调用str的strip()
方法:
#!/usr/bin/env python3 def trim(s): if(s==None or s == ''): return '' # 左侧空格 while(s[:1] == ' ' ): s = s[1:] # 右侧空格 while(s[-1:] == ' ' ): s = s[:-1] return s
测试数据
if trim('hello ') != 'hello': print('测试失败1!') elif trim(' hello') != 'hello': print('测试失败2!') elif trim(' hello ') != 'hello': print('测试失败3!') elif trim(' hello world ') != 'hello world': print('测试失败4!') elif trim('') != '': print('测试失败5!') elif trim(' ') != '': print('测试失败6!') else: print('测试成功!')