This “souwapy” is a library for summing array elements with high speed by new algorithm (Pyramid method). The speed is faster than csv and panbdas module of python and v8 engine of node.js. The souwapy module is 2.3 and 3.1 times faster than csv and pandas module, respectively. This was really surprised me. It was found that the theory was correct. At first, I have created this theory for Google Apps Script.