class Solution(object):
def isSubsequence(self, s, t):
"""
:type s: str
:type t: str
:rtype: bool
"""
if len(s) == 0:
return True
if len(s) > len(t):
return False
index = 0
for i in range(len(t)):
if t[i] == s[index]:
index += 1
if index == len(s):
return True
return False