CODEWITHSUNDEEP
pythonfunctionclassobjectimport
Cetus
Cetus

Reputation: 9

Python import from class

I am a novice Python programmer and I am practicing imports but I have a problem because I don't know how to import a program from a module, thanks in advance for your help. I have tried many solutions but always some error appears.... Folder (modul) --> missile.py --> Code of Class main.py

missile.py:

import math
import matplotlib.pyplot as plt

G = 9.81

class Missile():

    def __init__(self, Firing_angle, Initial_velocity):
        ...

    def equation_of_trajectory(self):
        ...

    def flight_path_envelope_for_constant_speed(self):
        ...

    def axis_of_symmetry(self):
        ...

    def velocity_of_flight(self):
        ...

    def elements_of_path(self):
        ...

    def call_block(self):
        a = Pr.equation_of_trajectory()
        b = Pr.flight_path_envelope_for_constant_speed()
        c = Pr.axis_of_symmetry()
        d = Pr.velocity_of_flight()
        e = Pr.elements_of_path()
        plt.plot(a)
        plt.plot(b)
        plt.plot( )
        plt.plot(d)
        plt.show( )
        return e

    def __str__(self):
            ...


if __name__ == '__main__':

    while True:
        try:
            Pr = Missile(float(input('Firing_angle       [o]:      ')),
                    float(input('Initial_velocity [m/s]:      ')))
            break
        except ValueError:
            print('Wrong Value!')

    resume = Pr.call_block()

    print(f'Projectile launch point [m]: {resume[0]}...)

main.py: ver.1

from Modul.missile import Missile

if __name__ == '__main__':
    Missile()

TypeError: __init__() missing 2 required positional arguments: 'Firing_angle' and 'Initial_velocity'
--------------------------------------------------------------------------------

ver.2

from Modul.missile import Missile

if __name__ == '__main__':
    Missile()

and

def __init__(self, Firing_angle=20, Initial_velocity=120):

result:

Process finished with exit code 0
--------------------------------------------------------------------------------

ver.3

from Modul.missile import Missile

if __name__ == '__main__':
    Firing_angle, Initial_velocity = Missile.call_block()

TypeError: call_block() missing 1 required positional argument: 'self'... etc..

I'm out of ideas on how to do this, thank you in advance for your help :D

Upvotes: 1

Views: 44

Answers (1)

Tim Roberts
Tim Roberts

Reputation: 54698

There are a couple of things here. Your first example is almost right. However, your call_block needs to use the self it is given, not the global Pr:

    def call_block(self):
        a = self.equation_of_trajectory()
        b = self.flight_path_envelope_for_constant_speed()
        c = self.axis_of_symmetry()
        d = self.velocity_of_flight()
        e = self.elements_of_path()
        plt.plot(a)
        plt.plot(b)
        plt.plot(c)
        plt.plot(d)
        plt.show()
        return e

The bigger thing is that all the code you have inside if __name__ == '__main__': actually needs to be in the main file. That code will never run when the file is imported. So, remove that code from the module, and make your main.py:

from Modul.missile import Missile

if __name__ == '__main__':
    while True:
        try:
            Pr = Missile(
                    float(input('Firing_angle       [o]:      ')),
                    float(input('Initial_velocity [m/s]:      ')))
            break
        except ValueError:
            print('Wrong Value!')

    resume = Pr.call_block()

    print(f'Projectile launch point [m]: {resume[0]}...)

Upvotes: 1

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