i actually had a very similar encounter with a Python near SOL last night. I had this mission to blow up some smugglers in a near system, and did that, killing about 4 of them and getting a reward, but rank is what i was doing it for. So after finishing it and flying back to the station i got the mission from, i suddenly got interdicted from insane distance. I didn't realize what it was, nor did i care since i'm a Bounty Hunter, interdicting me only saves me time from finding wanted peeps.
I gracefully accept the interdiction and tumble around a bit while i set my fire group for the KWS, and instantly i'm fired upon by tons of lasers, and some text saying something along the lines of "you're dead", only then i actually realized what had just interdicted me.. Only had 3 SCB's left from previous encounters, and about 30% ammo for my multicannon's since i had just come from a hunt, and was only expecting a small ship. This was the first time i got interdicted by something this vicious. Luckily after about 9 minutes of tense fighting i managed to destroy his powerplant and finish him off with my fully kitted viper, but still had massive damage, with about 31% hull integrity remaining, and my canopy full of cracks.
Solo's starting to get a bit dangerous at last.