Lazy Method for Reading Big File in Python?

Question

I have a very big file 4GB and when I try to read it my computer hangs. So I want to read it piece by piece and after processing each piece store the processed piece into an

Answer 1

f = ... # file-like object, i.e. supporting read(size) function and 
        # returning empty string '' when there is nothing to read

def chunked(file, chunk_size):
    return iter(lambda: file.read(chunk_size), '')

for data in chunked(f, 65536):
    # process the data

UPDATE: The approach is best explained in https://stackoverflow.com/a/4566523/38592