vectors_projections.py

print(
  '-----------------------------------------\n'\
  'Python Library for Linear Algebra Operations | Calculating projections of the entered vectors by user\n'\
  '-----------------------------------------\n'
  )

print(
  'Task:\n'\
  '-----------------------------------------\n'\
  'Write a simple Python module for calculating all necessary parameters projections of the entered vectors by user. You should calculate: \n- proj b (V) ;\n- orthogonal vector (V) ;\n- length of vector (V) ;\n'
  )

print(
  'Solution:\n'\
  '-----------------------------------------'\
  )

import os, sys, math

# Module for handling wrong data entered by user, along entering appropriate command:
class UnAcceptedValueError(Exception):
    def __init__(self, data):
        self.data = data
    def __str__(self):
        return repr(self.data)

#Module for creating a simple mathematical vectors on the dimension:
class Vector(object):
  def __init__(self, coordinates):
    try:
      if not coordinates:
        raise ValueError
      self.coordinates = tuple(coordinates)
      self.dimension = len(coordinates)

    except ValueError:
      raise ValueError('The coordinates must be nonempty')

    except TypeError:
      raise ValueError('The coordinate must be an iterable')

  def magnitude(self):
    coordinates_squared = [x**2 for x in self.coordinates]
    return math.sqrt(sum(coordinates_squared)) 

  def normalized(self):
    try:
      magnitude = self.magnitude()
      return [x * (1 / magnitude) for x in self.coordinates]
 
    except ZeroDivisionError:
      raise Exception('Cannot normalize the zero vector.')

  def __str__(self):
    return 'Vector {}'.format(self.coordinates)

  def __eq__(self, v):
    return self.coordinates == v.coordinates
    
# Default function for handling execution loop:\
def execution_loop():
    data = int(input("Do you want to try again ? Enter [1] - for continue / [0] - for quit : \n>>>"))
    if data == 1:
        return True
    elif data == 0:
        return False
    else:
        print('Error, you entered incorrect command. Please, try again...')
        execution_loop()

# Function for creating a two vectors for verifying:
def creating_vectors():
    vectors = []
    coordinate_counter = 1
    coordinate_input_control = True
    print('Please, enter all coordinates of the vector A:')
    vectors.append(Vector(coordinate_create('A')))
    print('Please, enter all coordinates of the vector B:')
    vectors.append(Vector(coordinate_create('B', size=vectors[0].dimension)))
    return vectors

# Function for interable creating a next coordinate of the vector:
def vector_loop(index):
    data = int(input("Do you want to add a new {0}-th coordinate ? Enter :\n[2] - for adding a new coordinate;\n[1] - for adding a new vector;\n>>>".format(index)))
    if data == 2:
        return 2
    elif data == 1:
        return 1
    else:
        print('Error: you entered incorrect command. Please, try again...')
        vector_loop()

# Function for loop-creating all coordinates of the selected vector:
def coordinate_create(name, **kwargs):
    vector = []
    coordinate_counter = 1
    coordinate_input_control = True
    size = kwargs.get('size', None)
    while coordinate_input_control:
        # print('Please, enter {0}-st coordinate:'.format(coordinate_counter))
        vector.append(vector_coordinate_input(coordinate_counter))
        if len(vector) == 3:
            print('You almost entered the maximum of coordinates of the {0} vector. The maximum number of coordinates should be less of equal to 3'.format(name))
            break
        elif len(vector) > 1:
            if name == 'A':
                data = vector_loop(2)
                if data == 2:
                    coordinate_input_control = True
                else:
                    coordinate_input_control = False
                    break
            else:
                if size == 2:
                    coordinate_input_control = False
                    break
                else:
                    coordinate_input_control = True
        coordinate_counter = coordinate_counter + 1
    print('You entered vector {0} with coordinates: {1}'.format(name, vector))
    return vector

# Function for creating every new coordinate of the vector:
def vector_coordinate_input(coordinate_counter):
    c_counter = coordinate_counter
    print('Please, enter {0}-st coordinate:'.format(c_counter))
    try:
        user_coordinate = float(input(">>>"))
        print('user_coordinate:')
        print(user_coordinate)
        return user_coordinate
    except SyntaxError:
        print("You cannot leave coordinate-field empty. Please, try enter any number...")
        vector_coordinate_input(c_counter)
    except KeyboardInterrupt:
        print("You cannot quit from the program here. Please, try enter any number...")
        vector_coordinate_input(c_counter)
    except:
        print("Coordinate of the vector should be only number. Please, try enter any number...")
        vector_coordinate_input(c_counter)

# Default loop for handling execution:
again_exec = True
counter_exec = 0

# Default loop for handling execution loop:
while again_exec:
    vectors = []
    vectors = creating_vectors()
    again_exec = execution_loop()
    counter_exec = counter_exec + 1

    # The end of execution:
    if again_exec == False:
        print('Program was executed: {0} times.'.format(counter_exec))
        break

print(
  '\n-----------------------------------------\n'\
  'Copyright 2019 Vladimir Pavlov. All Rights Reserved.\n'\
  '-----------------------------------------'
  )