Python Recipe: Read CSV/TSV Textfiles and Ignore Comment-lines

Scientific data commonly comes in tab-separated textfile format containing comment lines. What is the best way to read this data? Analogous to the recipe given by skip.montanaro, use a commented file decorator as follows:
import sys, re
import csv
class CommentedFile:
def __init__(self, f, commentstring=”#”):
self.f = f

Finding out where your Program Crashes with the Emacs GUD

This post describes a very, very elementary debugging skill. Yet, I could not find any concise tutorial about it on the web. So, here we go!
Assume you’re developing a small software under Linux, maybe using C or C++ and the GCC compiler. Testing your program, you find that it crashes with an error (segfault, assertion, [...]