Converting floating point to string in non-scientific format

Hi all: When I try to convert a float variable into string via repr() or str() function, i get the value as is, i.e '0.1e-7' in IEEE 754 format. Instead how can force the created string to represent the floating point in non-scientific fashion (non IEEE 754 format)? i.e something like 0.1

regd efficient methods to manipulate *large* files

Hi: This question is not directed "entirely" at python only. But since I want to know how to do it in python, I am posting here. I am constructing a huge matrix (m x n), whose columns n are stored in smaller files. Once I read m such files, my matrix is complete. I want to pass this matr