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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def particles_ascii(self, prec=8):
 """ Returns an ASCII string with all particles' masses, radii, positions and velocities. Parameters prec : int, optional Number of digits after decimal point. Default 8. """

        s = ""
        for p in self.particles:
            s += (("%%.%de "%prec) * 8)%(p.m, p.r, p.x, p.y, p.z, p.vx, p.vy, p.vz) + "\n"
        if len(s):
            s = s[:-1]
        return s