[Python] First python program, cannot understand error "takes 4 positional arguments but 5...

Below is my first serious go at a python 3.13 Class problem. I am self taught.

Please don't be put off by the maths. The program is simple, and the solution must be obvious to someone with a bit of coding experience.

A 1 kg particle 'p' orbits earth at sufficient height and velocity to get reasonably circular motion.

I started out with all variables being Class variables and whittled these down to 4(G , ME, t (time) and dt (time increment). All else are instance variables. There is one instance of class, called 'p'.

At 6th last line: p.move(p.r, p.rAng, p.v, p.vAng), I get the error:

TypeError: Particle.move() takes 4 positional arguments but 5 were given
​

import math
class Particle:
# CLASS VARIABLES and constants
G = 6.674e-11 # gravity constant kilogram metre second
ME = 5.972e24 # mass earth kg
t = 0 # start time
dt = 1 # time increment seconds

def __init__(self, r, rAng, v, vAng, potE, kinE, totalE):
self.r = r
self.rAng = rAng
self.v = v
self.vAng = vAng
self.potE = potE
self.kinE = kinE
self.totalE = totalE

def move(r, rAng, v, vAng):
a = -Particle.G * Particle.ME / r**2
ax = a * math.cos(rAng)
ay = a * math.sin(rAng)

vx = v * math.cos(vAng) + ax * Particle.dt
vy = v * math.sin(vAng) + ay * Particle.dt
v = (vx**2 + vy**2) ** 0.5
vAng = math.atan2(vy, vx)

rx = r * math.cos(rAng) + vx * Particle.dt + 0.5 * ax * Particle.dt**2
ry = r * math.sin(rAng) + vy * Particle.dt + 0.5 * ay * Particle.dt**2
r = (rx**2 + ry**2) ** 0.5
rAng = math.atan2(ry, rx)
potE = -Particle.G * Particle.ME / r
kinE = 0.5 * 1 * v**2
totalE = potE + kinE
Particle.t += Particle.dt

def result(t, r, rAng, totalE, potE, kinE):
print(
f"t: {Particle.t: >7,d} s\
r: {r/1000:6.3f} km\
rAng: {(rAng*180/3.14159):6.1f}deg\
totalE: {int(totalE*1.0E-6)}MJ\
potE: {int(potE*1.0E-6)}MJ\
kinE: {int(kinE*1.0E-6)}MJ"
)

p = Particle(12748e03, 0, 5592, math.pi / 2, 0, 0, 0)

while Particle.t < 13000:
p.move(p.r, p.rAng, p.v, p.vAng)
if Particle.t % 100 == 0:
p.result(Particle.t, p.r, p.rAng, p.totalE, p.potE, p.kinE)
else:
continue
Particle.t += Particle.dt


There are only 4 arguments. Python is interpreting 'p.move' as a 5th argument. I have tried deleting the references to 'p' in the arguments but that leads to more errors. The math stacks up ok, so its just an error of referencing between 'Particle' the class and 'p' the instance. I haven't been able to find anything understandable on the net. Can anyone help? Thanks.

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