切片
Topic sourcedef trim(s):
if s[:1] != ' ' and s[-1:] != ' ':
return s
else:
while s[:1] == ' ':
s = s[1:]
while s[-1:] == ' ':
s = s[:-1]
return s
return s
- 1
def trim(s):
if s[:1] != ' ' and s[-1:] != ' ':
return s
else:
while s[:1] == ' ':
s = s[1:]
while s[-1:] == ' ':
s = s[:-1]
return s
return s
Lumia
def trim(s):
if s[:1] != ' ' and s[-1:] != ' ': # 首尾不为空时直接返回
return s
elif s[0] == ' ':
return trim(s[1:]) # 首位为空，返回s[1:]
else:
return trim(s[:-1]) # 末位为空，返回 s[:-1]