leetcode70 python climb stairs

Suppose you are climbing stairs. It takes  n  steps to reach the top of the building.

You can climb 1 or 2 steps each time. How many different ways can you get to the top of a building?

Note: n is given   a positive integer.

Example 1:

Input: 2
 Output: 2
 Explanation: There are two ways to climb to the top of the building.
1. 1 step + 1 step
2. 2 steps

Example 2:

Input: 3
 Output: 3
 Explanation: There are three ways to climb to the top of the building.
1. 1 step + 1 step + 1 step
2. 1 step + 2 steps
3. 2 steps + 1 step

python code

class Solution:
    def climbStairs(self, n):
        """
        :type n: int
        :rtype: int
        """
        #Similar to Fibonacci practice
        result=[1,1]#Initialize the first level and the second level
        if n>=2:
            for i in range(2,n+1):
                result.append(result[i-1]+result[i-2])#The current result can come from the previous step or from the previous step, in two cases
        return result[n]