---

import math

class KM2():
    def __init__(self):
        self.set_params = {}
        
    def _calc_enthalpy(self, P_0):
        return 2500 + 100 * math.log(P_0)
        
    def __call__(self, mode):
        return self.calculate(mode)
        
    def calculate(self, mode):
        u_c_opt = 0.45
        G_ref = 100
        h0 = self._calc_enthalpy(self.set_params['P_0'])
        hkt = self._calc_enthalpy(self.set_params['P_k'])
        H0 = h0 - hkt
        
        if mode == 'diameter':
            Hi = H0 / self.set_params['z']
            c_ad = (2000 * Hi)**0.5
            u_opt = u_c_opt * c_ad
            D_pre = u_opt * 60 / (3.14 * self.set_params['n'])
            D = D_pre * (self.set_params['G'] / G_ref)**0.2
            return D
            
        if mode == 'stages':
            u = math.pi * self.set_params['D'] * self.set_params['n'] / 60
            for z in range(1, self.set_params['z'] + 1):
                Hi = H0 / z
                c_ad = (2000 * Hi)**0.5
                u_c_ratio = u / c_ad
                if abs(u_c_ratio - u_c_opt) < 0.1:
                    break
            return z

# Расчет 1
Res1 = KM2()
Res1.set_params = {'G': 100, 'P_0': 14.5, 'T_0': 545, 'P_k': 0.005, 'D': 1.2, 'z': 10, 'n': 3000}
result1 = Res1.calculate(mode='stages')
result2 = Res1.calculate(mode='diameter')
print('stages:', result1, 'diameter:', result2)

# Расчет 2
Res2 = KM2()
Res2.set_params = {'G': 200, 'P_0': 10.5, 'T_0': 545, 'P_k': 0.005, 'D': 1.5, 'z': 10, 'n': 3000}
result3 = Res2(mode='stages')
result4 = Res2(mode='diameter')
print('stages:', result3, 'diameter:', result4)