Working on different projects I have the choice of selecting different programming languages, as long as the task is done.
I was wondering what the real difference is, in terms of performance, between writing a program in Python, versus doing it in C.
The tasks to be done are pretty varied, e.g. sorting textfiles, disk access, network access, textfile parsing.
Is there really a noticeable difference between sorting a textfile using the same algorithm in C versus Python, for example?
And in your experience, given the power of current CPU's (i7), is it really a noticeable difference (Consider that its a program that doesnt bring the system to its knees).
If your text files that you are sorting and parsing are large, use C. If they aren't, it doesn't matter. You can write poor code in any language though. I have seen simple code in C for calculating areas of triangles run 10x slower than other C code, because of poor memory management, use of structures, pointers, etc. 
Your I/O algorithm should be independent of your compute algorithm. If this is the case, then using C for the compute algorithm can be much faster.
Performance differences between Python and C