Both do well in a Resource Extraction Site(RES), so here is a rundown on various points comparing the Anaconda to the python:
Shields:
the Anaconda has a bit more staying power due to it being capable of having shields that have more than twice the MJ's of the pythons* (based on using A6 shields with 7 A rated shield boosters compared to A6 shields in python with 3-4 A rated shield boosters). However, the Anaconda is less able to avoid damage than the python. Both ships do well with shield cell banks, but the Anaconda can carry more, but each charge will seem to do less for the Anaconda as its shields are generally a much larger capacity.
Weapons: The Anaconda has more weapons and depending on build, can fire them slightly longer than the python, but unless they are turret mounted, the Anaconda has more trouble bringing the weapons to bear on a target at close range (under 1km). The python can more easily bear its weapons on a target at closer range (under 750m). Also note that at under 200m, not all the weapons on an Anaconda will be able to hit the same target and at under 100m the nose of the anaconda will impact the target if it is directly ahead, possibly preventing either the top or bottom mounted weapons from being able to hit. In short, the Anaconda has more and bigger weapons, but has issues with being able to hit a target with all of them at the same time.
Maneuverability: The python pretty much wins this category over the Anaconda, especially for speed at 0 pips to engines, pitch up/down rate, and acceleration/deceleration. The only thing the Anaconda does better is it takes a longer time for its boost speed to decay back to normal full throttle, but this is balanced out by it having a hard time stopping itself suddenly.
Ramming: While both ships are good at ramming attacks, the python is more likely to hit its target, while the Anaconda is better able to withstand the impact along with doing more damage. If you favor using a ramming attack as your opening move against an npc, either ship will do fine, but the Anaconda can do this more often before it starts to take damage. The general difficulty of hitting a ship that is able to move faster than you does detract from this tactic for the Anaconda
Escaping: The Anaconda will be mass inhibited less often but if you need to get a distance away the Python is generally better as it travels faster.
Summary: Both ships have their strong points and weak points, and at the end of the day, the ship that is better for a RES site (yes I know technically that is saying site twice) is the ship that better suits your playstyle, as the Anaconda played as a shoulder things aside tank that is easiest flown with turrets will do just as well as a Python played as a maneuverable heavy fightercraft that can absorb a lot of punishment.