leetcode python

# The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)## P   A   H   N# A P L S I I G# Y   I   R# And then read line by line: "PAHNAPLSIIGYIR"# Write the code that will take a string and make this conversion given a number of rows:## string convert(string text, int nRows);# convert("PAYPALISHIRING", 3) should return "PAHNAPLSIIGYIR".class Solution(object):    def convert(self, s, numRows):        """        :type s: str        :type numRows: int        :rtype: str        """        if numRows <= 1:            return s        result = ''        cycle = 2 * numRows - 2        for i in xrange(numRows):            for j in xrange(i, len(s), cycle):                result += s[j]                j2 = (j - i) + cycle - i                if i != 0 and i != numRows - 1 and j2 < len(s):                    result += s[j2]        return result