def trim(s):
n = 0
m = 0
l = 0
for i in range(len(s)):
if s[i] == ' ':
l = l + 0
else:
l = l + 1
if l == 0:
s = s[:0]
return s
else:
for i in range(len(s)):
if s[i] == ' ':
n = n+1
else:
break
for i in range(len(s)):
if s[-(i+1)] == ' ':
m = m+1
else:
break
if m == 0:
s = s[n:]
else:
s=s[n:-m]
return s
常常23333
def trim(s): n = 0 m = 0 l = 0 for i in range(len(s)): if s[i] == ' ': l = l + 0 else: l = l + 1 if l == 0: s = s[:0] return s else: for i in range(len(s)): if s[i] == ' ': n = n+1 else: break for i in range(len(s)): if s[-(i+1)] == ' ': m = m+1 else: break if m == 0: s = s[n:] else: s=s[n:-m] return s
if trim('hello ') != 'hello': print('测试失败!%d'%(1)) elif trim(' hello') != 'hello': print('测试失败!%d'%(2)) elif trim(' hello ') != 'hello': print('测试失败!%d'%(3)) elif trim(' hello world ') != 'hello world': print('测试失败!%d'%(4)) elif trim('') != '': print('测试失败!%d'%(5)) elif trim(' ') != '': print('测试失败!%d'%(6)) else: print('测试成功!')