python-examples.py

# ================================== V.03.2 ================================== #
# Updated python-examples to version 3.2
# - exercise_11 has some error messages for user input routine
# - tweaked logical tests to be more readable
#
# ============================================================================ #


import datetime
import numpy as np
import matplotlib
# matplotlib.use('PDF')
import matplotlib.pyplot as plt


''' ======= EXERCISE ROUTINES ======='''


def exercise_1():
    print('hello world')


def exercise_2():
    for n in range(0, 50):
        print('foo bar ' + str(n))


def exercise_3():
    for n in range(0, 50):
        if n % 5 == 0:
            print('foo bar ' + str(n))


def exercise_4():
    for n in range(0, 50):
        if n % 2 == 0:
            print('good bye world ' + str(n))
        else:
            print('hello world ' + str(n))


def exercise_5():
    # Read in the text file ‘xy.txt’ and print the data to the terminal in 2 columns
    x, y = np.loadtxt('DATA/xy.txt', unpack=True)
    num_of_items = len(x)
    print('Number of data plots is ' + str(num_of_items))
    counter = 0
    print('===== BEGIN PRINT ITEMS =====')
    print('x', ' | ', 'y')
    while counter < num_of_items:
        print(x[counter], ' | ', y[counter])
        counter += 1
    print('===== END PRINT ITEMS =====')


def exercise_6():
    # Plot the data in ‘xy.txt’ with blue dots
    x, y = np.loadtxt('DATA/xy.txt', unpack=True)
    plt.plot(x, y, 'r+')
    plt.show()


def exercise_7():
    print('Task: Plot the data in ‘xy.txt’ with red crosses')
    x, y = np.loadtxt('DATA/xy.txt', unpack=True)
    fig = plt.figure()  # Initialise the figure for plotting onto
    plt.plot(x, y, 'r+')
    # plt.show()
    filename = make_file_name_with_date(directory='Plots', name_stub='plot-exercise_7-', extension='.png')
    fig.savefig(filename)
    print('** Plot saved as ' + filename + ' **')


def exercise_8():
    print('Task: Plot the data in ‘xy.txt’ as a line plot')
    x, y = np.loadtxt('DATA/xy.txt', unpack=True)
    fig = plt.figure()  # Initialise the figure for plotting onto
    plt.plot(x, y, '-m')
    # plt.show()
    filename = make_file_name_with_date(directory='Plots', name_stub='plot-exercise_8-', extension='.png')
    fig.savefig(filename)
    print('** Plot saved as ' + filename + ' **')


def exercise_9():
    print('''Task: Find the individual sums of the 'x' data and the 'y' data and
    print them to the terminal''')
    x, y = np.loadtxt('DATA/xy.txt', unpack=True)
    num_of_items = len(x)
    counter = 0
    while counter < num_of_items:
        temp_x = x[counter]
        temp_y = y[counter]
        print('{} + {} = {}'.format(str(temp_x), str(temp_y), temp_x + temp_y))
        counter += 1


def exercise_9_a():
    print('''Task: Find the individual sums of the ‘x’ data and the ‘y’ data and
    print them to the terminal''')
    x, y = np.loadtxt('DATA/xy.txt', unpack=True)
    x_and_y = np.vstack((x, y)).T
    print(np.sum(x_and_y, axis=1))


def exercise_10():
    print('''Task: 10. Determine the individual means for the ‘x’ and ‘y’ data and print them to
    the terminal''')
    x, y = np.loadtxt('DATA/xy.txt', unpack=True)
    x_and_y = np.vstack((x, y)).T
    print(np.mean(x_and_y, axis=1))


def exercise_11():
    print('''Task: 11. Write a code that creates 3 variables called 
    ‘day’, ‘month’, ‘year’. Get the code to ask the user to input
    values for each variable, and then output the values in the form 
    "Today's date is:" dd/mm/yyyy.
    Now run the code using today's date as the input.''')
    day = 0
    day_is_valid = False
    month = 0
    month_is_valid = False
    year = 0
    year_is_valid = False
    variables = [[day, 'day', day_is_valid], [month, 'month', month_is_valid], [year, 'year', year_is_valid]]
    variables = {'day': 0, 'month': 0, 'year': 0}
    variable_validity = {'day': False, 'month': False, 'year': False}

    input_message = 'Input the <variable> for today\'s date as an integer:  '

    while not variable_validity['day'] or not variable_validity['month'] or not variable_validity['year']:
        for variable_name in variables.keys():  # Gets key names for variables dict as list
            if not variable_validity[variable_name]:
                variables[variable_name] = int(input(input_message.replace('<variable>', variable_name)))
        day = variables['day']
        month = variables['month']
        year = variables['year']
        variable_validity['day'], variable_validity['month'], variable_validity['year'] = \
            check_date_validity(day, month, year)

    """
    while not variables[0][2] or not variables[1][2] or not variables[2][2]:
        print('Back to while loop')
        for variable in variables:
            if not variable[2]:
                variable[0] = int(input(input_message.replace('<variable>', variable[1])))
        day = variables[0][0]
        month = variables[1][0]
        year = variables[2][0]
        variables[0][2], variables[1][2], variables[2][2] = check_date_validity(day, month, year)
    """

    date_str = f'{str(day)}/{str(month)}/{str(year)}'
    print(f'"Inputted date is:" {date_str}.')


def check_date_validity(day, month, year):
    # Sub routine for exercise_11
    day_is_valid = False
    month_is_valid = False
    year_is_valid = False

    if 2010 <= year <= 2050 and str(type(year)) == "<class 'int'>":
        year_is_valid = True
        print('** Year is valid **')
    else:
        print('!! Inputted year is not valid, input an integer between 2010 and 2050 !!')

    if 1 <= month <= 12 and str(type(month)) == "<class 'int'>":
        month_is_valid = True
        print('** Month is valid **')
    else:
        print('!! Inputted month is not valid, input an integer between 1 and 12 !!')

    if year_is_valid:
        if leap_year_check(year):
            extra_day = 1
        else:
            extra_day = 0
    else:
        extra_day = 0

    days_in_months = [31, 28 + extra_day, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]

    if month_is_valid:
        if 1 <= day <= days_in_months[month - 1] and str(type(day)) == "<class 'int'>":
            day_is_valid = True
            print('** Day is valid **')
        else:
            print(f'!! Inputted day is not valid, input an integer between 0 and {days_in_months[month - 1]} !!')

    return day_is_valid, month_is_valid, year_is_valid


def leap_year_check(year):
    # Sub routine for exercise_11
    if year % 4 != 0:
        return False
    if year % 100 != 0:
        return True
    if year % 400 != 0:
        return False
    else:
        return True


''' ===== END EXERCISE ROUTINES ====='''


list_of_exercises = [exercise_1, exercise_2, exercise_3, exercise_4,
                     exercise_5, exercise_6, exercise_7, exercise_8,
                     exercise_9, exercise_9_a, exercise_10, exercise_11]


def generate_current_date_str():
    date_format = 'yyyy-mm-dd'
    current_date = datetime.datetime.now()
    year = str(current_date.year)
    month = current_date.month
    if month < 10:
        month = '0' + str(month)
    else:
        month = str(month)
    date = current_date.day
    if date < 10:
        date = '0' + str(date)
    else:
        date = str(date)

    # Get date format str and replace components
    current_date_str = date_format.replace('yyyy', year).replace('mm', month).replace('dd', date)

    return current_date_str


def make_file_name_with_date(directory, name_stub, extension):
    return directory + '/' + name_stub + generate_current_date_str() + extension


def headline(text, symbol, width):
    return f" {text} ".center(width, symbol)


''' ===== EXECUTION ====='''


def output_all():
    counter = 0
    while counter < len(list_of_exercises):
        print(headline(width=50, text='Start ' + list_of_exercises[counter].__name__, symbol='='))
        list_of_exercises[counter]()  # Run the exercise routine for this counter
        print(headline(width=50, text='End ' + list_of_exercises[counter].__name__, symbol='=') + '\n\n')
        counter += 1


valid_selection = False
while not valid_selection:
    user_selection = input('Do you want to run one exercise or all exercises?\nChoose "one" or "all": ')
    if user_selection != 'one' and user_selection != 'all':
        print('Invalid selection, type "one" or "all" only.  Please try again.\n\n')
    if user_selection == 'all':
        valid_selection = True
        output_all()
    if user_selection == 'one':
        valid_selection = True
        counter = 1
        for n in list_of_exercises:
            # Present a list of available exercises to the user for selection
            print(str(list_of_exercises.index(n) + 1) + ' : ' + str(n.__name__))
            counter += 1
        # New while loop to ensure valid exercise option is chosen
        valid_exercise = False
        while not valid_exercise:
            try:
                # User input is 1 indexed, list is 0 indexed so -1 to compensate
                user_selected_exercise = int(
                    input('Select the exercise to run by the corresponding number shown above: ')) - 1
                # Check that user input is in range of list
                if 0 <= user_selected_exercise < len(list_of_exercises):
                    valid_exercise = True
                else:
                    print('Invalid selection, type a number that is between 1 and ' +
                          str(len(list_of_exercises)) +
                          '.  Please try again.\n\n')
            except:
                print('Invalid selection, type only a number that is between 1 and ' +
                      str(len(list_of_exercises)) +
                      '.  Please try again.\n\n')

        print(headline(width=50, text='Start ' + list_of_exercises[user_selected_exercise].__name__, symbol='='))
        list_of_exercises[user_selected_exercise]()  # Run the exercise selected by user
        print(headline(width=50, text='End ' + list_of_exercises[user_selected_exercise].__name__, symbol='=') + '\n\n')

''' ===== END EXECUTION ====='''