Extract specific text lines?

Question

I have a large several hudred thousand lines text file. I have to extract 30,000 specific lines that are all in the text file in random spots. This is the program I have to extr

Answer 1

According to Python's documentation of file objects, iteration you're doing should not be especially slow, and search for substrings should also be fine speed-wise.

I don't see any reason why your code should be slow, so if you need it to go faster you might have to rewrite it in C and use mmap() for fast access to the source file.