This is not debate or geeky question, It is simple as it is
sed program is a stream editor,AWK is an interpreted programming language designed for text processing and typically used as a data extraction and reporting tool wikipedia , perl and python are programming languages and here in biostars a lot of talks cover perl vs python topic When To Choose Python Over Perl (And Vice Versa)?
My question If you already knows Perl or python is it worth to learn Sed and Awk?
From your experience which tool of the four helped you best in solving bioinformatics problem and in what situation?
Conclusion: Which to use when?