The linecache module

This module is used to read lines from module source code. It caches recently visited modules (the entire source file, actually).

Example: Using the linecache module

# File: linecache-example-1.py

import linecache

print linecache.getline("linecache-example-1.py", 5)

$ python linecache-example-1.py
print linecache.getline("linecache-example-1.py", 5)

This module is used by the traceback module.