Creating a new file, filename contains loop variable, python

Question

I want to run a function over a loop and I want to store the outputs in different files, such that the filename contains the loop variable. Here is an example

Answer 1

Concatenate the i variable to a string as follows:

f = open("file_"+str(i)+".dat","w")

OR

f = open("file_"+`i`+".dat","w") # (`i`) - These are backticks, not the quotes.

See here for other techniques available.