<LeetCode><Easy> 6 ZigZag Conversion

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"

.

#Python2 156ms

class Solution(object):
def convert(self, s, numRows):
"""
:type s: str
:type numRows: int
:rtype: str
"""
if numRows<2:
return s
numRows2=2*numRows-2
dictRows={i:[] for i in range(numRows)}
for i in range(len(s)):
location=i%numRows2
if location>=numRows:
location=numRows2-location
dictRows[location].append(s[i])
rString=""
for i in range(numRows):
rString+="".join(dictRows[i])
return rString