不必死磕 多次提交，每次修改代码即可

class Solution(object):
    def isNumber(self,s):
        s=s.strip()
        #去除空格
        if not s:
            return False
        if s[0]=='+' or s[0]=='-':
            s=s[1:]
        if not s or s[0]=='+' or s[0]=='-' or s[0]=='.' and len(s)==1:
            return False
        dot=0
        Ee=0
        num=0
        for i in range(len(s)):
            char=s[i]
            if '0'<=char<='9':
                num+=1
            elif char=='+' or char=='-':
                if not (s[i-1]=='e' or s[i-1]=='E'):
                    return False
            elif char=='.':
                dot+=1
                if dot>1:
                    return False
                if Ee:
                    return False
            elif char=='e' or char=='E':
                Ee+=1
                if num==0:
                    return False
                if i==0:
                # E e 开头
                    return False
                if i+1==len(s):
                # E e 结尾
                    return False
                if Ee>1:
                    return False
                if s[i+1]=='+' or s[i+1]=='-':
                    if i+2==len(s):return False
            else:
                return False
        return True