寻找最大连续子串和以及寻找最长数字串

'''寻找最大连续子串和'''
def find_max_sub_sum(data):
	if not data:
		return None
	sub = data[0]
	submax = data[0]
	for i in range(1, len(data)):
		sub = max(sub+data[i], data[i])
		submax = max(submax, sub)
	return submax

'''寻找最长的数字串'''
def find_longest_num(s):
	if not s:
		return ''
	i = 0
	maxNumLen = 0
	while i < len(s):
		if s[i].isdigit():
			startNum = i
			numLen = 0
			while i < len(s) and s[i].isdigit():
				numLen += 1
				i += 1
			'''比较长度是否超过前面保存的最大长度，这里如果有相同长度的子串，则取后面的，如果要取前面的，则maxNumLen < numLen即可'''
			if numLen and maxNumLen <= numLen:
				maxNumLen = numLen
				sub = ''    #每次sub需要清空
				for j in range(startNum,startNum+numLen):
					sub += s[j]
		i += 1
	return sub,maxNumLen


if __name__ == '__main__':
	str = 'abcd12345ed123ss123456789'
	b = [-2, -1 ,3 ,-6, 20, 7, -34]
	print(find_longest_num(str)) #('123456789', 9)
	print(find_max_sub_sum(b)) #27