Nobody else did, so I'll state the obvious.
Python is slow, that is true. From a little experience doing some heavy math, a good rule of thumb is about 1000 times slower than C (for simple stuff, you can safely assume that that's as fast as it gets). The point is that this doesn't mean Python is a bad language, nor that it doesn't have its uses, it only means that when doing heavy duty work, you shouldn't use Python. I wouldn't write a database, a 3D graphics engine, or a quantum mechanics simulation in Python.
That said, 99.99% of what you do these days is not performance-critical. One has to appreciate the fact that if I have a .csv file containing fields in one order, and I need to manipulate the fields a little, rearrange them, and dump them into a different file format - it takes 5 minutes back to back with Python, when it'll take me half an hour in C. Unless that file happens to be quite large, a few gigs at least, there's no way I'll write in C. If I want to solve an exercise, say, finding a fiveleaper's tour, Python will take me much less time. If I want to write an interactive web interface, I'll probably use Django.
The last point in favor of Python is that beyond mere development speed, Python is much, much more user friendly and I believe more beginner friendly. Compare:
#include <stdio.h>
int main() {
printf("Hello world!");
return 0;
}
with
Try writing a simple TCP socket chat client/server, and the difference becomes much more obvious.