交作业，看大佬们的都写得简单。。。。。。。。
Topic source
测试成功
def trim(s): if s[0:2]==' ' and s[len(s)-2:len(s)]==' ': return s[2:-2] elif s[0:2]==' ': return s[2:len(s)] elif s[len(s)-2:len(s)]==' ': return s[0:-2] else: return s
def trim(s):
if s[0:2]==' ' and s[len(s)-2:len(s)]==' ':
return s[2:-2]
elif s[0:2]==' ':
return s[2:len(s)]
elif s[len(s)-2:len(s)]==' ':
return s[0:-2]
else:
return s
测试成功
- 1
emmmm变大了
def trim(s):
l=0
while l<len(s):
print(s)
if s[0:1]==' ':
print('判断头是否有空格')
if s[-2:-1]==' ':
print('头尾都有空格')
s=s[2:-2]
break
else:
print('只有头有空格')
print(s)
s=s[2:]
break
elif s[-2:-1]==' ':
s=s[0:-2]
print('判断尾是否有空格',s)
break
else:
print('只有空格')
s=s
break
print('当前字符串：', s)
return s