The project below explains how to build a simple chat bot called Monty, adding functionality in small incremental steps. The weekly project was part of TE3201-Software Engineering (Weekly Project)
Write a Python program to read in one user command and repeat it back to the user. An example output is given below. (Solution)
>>> Hello, my name is Monty
>>> What can I do for you?
foo
>>> Your command is: foo
>>> Bye!
Extend Monty 1 code to work as follows. (Solution)
>>> Hello, my name is Monty
>>> What can I do for you?
list
>>> Nothing to list
>>> What can I do for you?
foo
>>> OOPS! Unknown command
>>> What can I do for you?
exit
>>> Are you sure? y/n
n
>>> What can I do for you?
exit
>>> Are you sure? y/n
y
>>> Bye!
Restructure the Monty 2 code to fit the following structure, while keeping the behavior same as Monty 2. (Solution)
import sys
# ADD MISSING METHODS
def main():
print_greeting()
while True:
command = read_command()
execute_command(command)
main()Enhance the Monty 3 code to improve the functionality as per the sample output given below. (Solution)
>>> Hello, my name is Monty
>>> What can I do for you?
list
>>> Nothing to list
>>> What can I do for you?
add read book
>>> What can I do for you?
list
>>> List of items:
1. read book
>>> What can I do for you?
add return book
>>> What can I do for you?
list
>>> List of items:
1. read book
2. return book
>>> What can I do for you?
exit
>>> Are you sure? y/n
y
>>> Bye!Enhance the Monty 4 code in the following ways:
- Add a done command so that the user can mark a task as done. e.g., done 2 marks the task at index 2 as 'done'.
- Show appropriate error messages if the user gives an invalid index for the done command
A sample output is given below. (Solution)
>>> Hello, my name is Monty
>>> What can I do for you?
add borrow book
>>> What can I do for you?
add read book
>>> What can I do for you?
add return book
>>> What can I do for you?
list
>>> List of items:
[✗] 1. borrow book
[✗] 2. read book
[✗] 3. return book
>>> What can I do for you?
done 1
>>> What can I do for you?
list
>>> List of items:
[✓] 1. borrow book
[✗] 2. read book
[✗] 3. return book
>>> What can I do for you?
done abc
>>> SORRY, I could not perform that command. Problem: abc is not a number
>>> What can I do for you?
done 5
>>> SORRY, I could not perform that command. Problem: No item at index 5
>>> What can I do for you?
done 0
>>> SORRY, I could not perform that command. Problem: Index must be greater than 0
>>> What can I do for you?
garbage
>>> SORRY, I could not perform that command. Problem: Command not recognized
>>> What can I do for you?
exit
>>> Are you sure? y/n
y
>>> Bye!
💡 Each task has two data values: the description and the 'done' status. You can use a list to hold these two data items. That means your list of tasks will be a list containing lists. Example:
tasks = []
tasks.append(['read book', False])
print('Description of the first task:', tasks[0][0])
if tasks[0][1]:
print('✓')
else:
print('✗')💡 You can use exceptions to identify and handle errors in the command.
def main():
print_greeting()
while True:
try:
command = read_command()
execute_command(command)
except Exception as e:
print('>>> SORRY, I could not perform that command. Problem:', e)Enhance the Monty 5 code in the following ways:
- Add a help command so that the user can view how to use the app.
- Improve the formatting of the text displayed to the user to make the user experience nicer.
A sample output is given below. (Solution)
*******************************************************************************************
* __ __ _ _ __ __ _ *
* \ \ / / | | | | | \/ | | | *
* \ \ /\ / /__| | ___ ___ _ __ ___ ___ | |_ ___ | \ / | ___ _ __ | |_ _ _ *
* \ \/ \/ / _ \ |/ __/ _ \| '_ ' _ \ / _ \ | __/ _ \ | |\/| |/ _ \| '_ \| __| | | | *
* \ /\ / __/ | (_| (_) | | | | | | __/ | || (_) | | | | | (_) | | | | |_| |_| | *
* \/ \/ \___|_|\___\___/|_| |_| |_|\___| \__\___/ |_| |_|\___/|_| |_|\__|\__, | *
* __/ | *
* |___/ *
*******************************************************************************************
>>> What can I do for you?
help
>>> I'm glad you asked. Here it is:
==================================================
Monty can understand the following commands:
add DESCRIPTION
Adds a task to the list
Example: add read book
done INDEX
Marks the task at INDEX as 'done'
Example: done 1
exit
Exits the application
help_info
Shows the help_info information
list
Lists the tasks in the list
--------------------------------------------------
>>> What can I do for you?
add read book
>>> Task added to the list
>>> What can I do for you?
add return book
>>> Task added to the list
>>> What can I do for you?
done 1
>>> Congrats on completing a task! :-)
>>> What can I do for you?
list
>>> Here is the list of tasks:
==================================================
STATUS | INDEX | DESCRIPTION
--------------------------------------------------
✓ | 1 | read book
✗ | 2 | return book
--------------------------------------------------
>>> What can I do for you?Enhance the Monty 6 code in the following ways:
- Monty saves tasks into a csv file.
- Add a delete command that can delete a task at a specific index.
A sample output is given below. Note the following: (Sotion)
- Monty is able to show at the very start the three tasks loaded from the file.
- When item 2 is deleted, the item previously at index 3 moves to position 2.
*******************************************************************************************
* __ __ _ _ __ __ _ *
* \ \ / / | | | | | \/ | | | *
* \ \ /\ / /__| | ___ ___ _ __ ___ ___ | |_ ___ | \ / | ___ _ __ | |_ _ _ *
* \ \/ \/ / _ \ |/ __/ _ \| '_ ' _ \ / _ \ | __/ _ \ | |\/| |/ _ \| '_ \| __| | | | *
* \ /\ / __/ | (_| (_) | | | | | | __/ | || (_) | | | | | (_) | | | | |_| |_| | *
* \/ \/ \___|_|\___\___/|_| |_| |_|\___| \__\___/ |_| |_|\___/|_| |_|\__|\__, | *
* __/ | *
* |___/ *
*******************************************************************************************
>>> What can I do for you?
list
>>> Here is the list of tasks:
==================================================
STATUS | INDEX | DESCRIPTION
--------------------------------------------------
✓ | 1 | borrow book
✗ | 2 | read book
✗ | 3 | return book
--------------------------------------------------
>>> What can I do for you?
delete 2
>>> Task deleted from the list
>>> What can I do for you?
list
>>> Here is the list of tasks:
==================================================
STATUS | INDEX | DESCRIPTION
--------------------------------------------------
✓ | 1 | borrow book
✗ | 2 | return book
--------------------------------------------------
💡 here are some tips:
- The filename can be specified in the code. e.g.,
DATA_FILE = monty_7.csv - The format of the file is up to you. Here is an example:
borrow book,done
read book,pending
return book,pending- The program can load the tasks from the file at the beginning. It can save the data after each command. For example, as follows:
items = []
DATA_FILE = 'monty7.csv'
def main():
load_data(DATA_FILE) # load task data from the file
print_greeting()
while True:
try:
command = read_command()
execute_command(command)
save_data(DATA_FILE, items) # save all tasks in the file
except Exception as e:
print('>>> SORRY, I could not perform that command. Problem:', e)
main()Given below are some more features you can consider adding at this point (it is optional to add them to Monty 7):
- Remove the the need for the user to confirm before exiting Monty. As data are saved to a file, such a confirmation is no longer necessary because an accidental exit will not cause any permanent damage.
>>> What can I do for you?
exit
>>> Bye!- Add a
pendingcommand that can mark a task as pending (i.e., the opposite of thedonecommand).
>>> What can I do for you?
list
>>> Here is the list of tasks:
==================================================
STATUS | INDEX | DESCRIPTION
--------------------------------------------------
✓ | 1 | borrow book
✗ | 2 | read book
✗ | 3 | return book
--------------------------------------------------
>>> What can I do for you?
pending 1
>>> OK, I have marked that item as pending
>>> What can I do for you?
list
>>> Here is the list of tasks:
==================================================
STATUS | INDEX | DESCRIPTION
--------------------------------------------------
✗ | 1 | borrow book
✗ | 2 | read book
✗ | 3 | return book
--------------------------------------------------
>>> What can I do for you?- Make commands case insensitive and immune to extra leading/trailing spaces. For example, all these commands should work the same way.
add read book
ADD read book
Add read book
add read book
add read bookEnhance the Monty 7 code to add support for keeping track of deadlines as well as regular todo tasks
Previous behavior:
- add buy book: adds a task buy book
Proposed change - replace the above command with the following two:
- todo read book: adds a todo task read book
- deadline return book by: May 3rd adds a deadline return book which is to be done by May 3d. Note: by: is a keyword. Anything that comes after it is considered a description of the deadline.
A sample output is given below. (Solution)
>>> What can I do for you?
list
>>> Here is the list of tasks:
============================================================
STATUS | INDEX | DESCRIPTION | DEADLINE
------------------------------------------------------------
✓ | 1 | borrow book | -
✗ | 2 | read book | -
✗ | 3 | return book | Monday
------------------------------------------------------------
>>> What can I do for you?
todo watch movie
>>> What can I do for you?
deadline submit assignment by: end of May
>>> What can I do for you?
list
>>> Here is the list of tasks:
============================================================
STATUS | INDEX | DESCRIPTION | DEADLINE
------------------------------------------------------------
✓ | 1 | borrow book | -
✗ | 2 | read book | -
✗ | 3 | return book | Monday
✗ | 4 | watch movie | -
✗ | 5 | submit assignment | end of May
------------------------------------------------------------
>>> What can I do for you?Enhance the Monty 8 code to use classes ToDo and Deadline (i.e., you need to define these two classes) to represent todo tasks and deadlines, respectively. (Solution)
Enhance the Monty 9 code to extract the following classes:
UserInterface: an object of this class can be used to handle reading input from the user and showing output back to the user.StorageManager: an object of this class can be used to read data from the data file and write data back to the data file.TaskManager: an object of this class will hold the list of Task/Deadline objects and will execute commands.
Optional feature to consider: add a progress command that shows how many tasks/deadlines were marked as done during a session so far. Here is an example output:
(Solution)
>>> What can I do for you?
list
>>> Here is the list of tasks:
============================================================
STATUS | INDEX | DESCRIPTION | DEADLINE
------------------------------------------------------------
✓ | 1 | borrow book | -
✗ | 2 | read book | -
✗ | 3 | return book | Monday
------------------------------------------------------------
>>> What can I do for you?
progress
>>> Progress for this session: todos 0 deadlines 0
>>> What can I do for you?
done 2
>>> Congrats on completing a task! :-)
>>> What can I do for you?
progress
>>> Progress for this session: todos 1 deadlines 0
>>> What can I do for you?
done 3
>>> Congrats on completing a task! :-)
>>> What can I do for you?
progress
>>> Progress for this session: todos 1 deadlines 1
>>> What can I do for you?
pending 2
>>> OK, I have marked that item as pending
>>> What can I do for you?
progress
>>> Progress for this session: todos 0 deadlines 1
>>> What can I do for you?
list
>>> Here is the list of tasks:
============================================================
STATUS | INDEX | DESCRIPTION | DEADLINE
------------------------------------------------------------
✓ | 1 | borrow book | -
✗ | 2 | read book | -
✓ | 3 | return book | Monday
------------------------------------------------------------
>>> What can I do for you?
Enhance the *Monty 10 code to make the Deadline class inherit from the ToDo class:
(Solution)
Enhance the Monty 11 code to divide the source code into multiple files (e.g., todo.py, deadline.py, etc.).
(Solution)
Add some unit tests to Monty 12 code. (Solution)
Enhance the Monty 13 code to integrate it with the skeletal GUI given below.
Notes about the given version of the GUI:
- The GUI shows the list of tasks all the time.
- It initializes with some dummy data.
- It only supports an add command and a help command.
Here are some screenshots of the GUI: (Solution)
import datetime
from tkinter import *
import sys
class GUI:
def __init__(self, task_manager):
self.task_manager = task_manager
self.window = Tk()
self.window.geometry('800x700') # set Window size
self.window.title('Monty') # set Window title
self.input_box = Entry(self.window) # create an input box
self.input_box.pack(padx=5, pady=5, fill='x') # make the input box fill the width of the Window
self.input_box.bind('<Return>', self.command_entered) # bind the command_entered function to the Enter key
self.input_box.focus() # set focus to the input box
# add a text area to show the chat history
self.history_area = Text(self.window, width="50")
self.history_area.pack(padx=5, pady=5, side=LEFT, fill="y")
self.output_font = ('Courier New', 12)
self.history_area.tag_configure('error_format', foreground='red', font=self.output_font)
self.history_area.tag_configure('success_format', foreground='green', font=self.output_font)
self.history_area.tag_configure('normal_format', font=self.output_font)
# add a text area to show the list of tasks
self.list_area = Text(self.window)
self.list_area.pack(padx=5, pady=5, side=RIGHT, fill="both")
self.list_area.tag_configure('normal_format', font=self.output_font)
self.list_area.tag_configure('pending_format', foreground='red', font=self.output_font)
self.list_area.tag_configure('done_format', foreground='green', font=self.output_font)
# show the welcome message and the list of tasks
self.update_chat_history('start', 'Welcome to Monty!', 'success_format')
self.update_task_list(self.task_manager.items)
def update_chat_history(self, command, response, status_format):
"""
status_format: indicates which color to use for the status message
can be 'error_format', 'success_format', or 'normal_format'
"""
current_time = datetime.datetime.now().strftime("%H:%M:%S")
self.history_area.insert(1.0, '-' * 40 + '\n', 'normal_format')
self.history_area.insert(1.0, '>>> ' + response + '\n', status_format)
self.history_area.insert(1.0, 'You said: ' + command + '\n', 'normal_format')
self.history_area.insert(1.0, current_time + '\n', 'normal_format')
def update_task_list(self, tasks):
self.list_area.delete('1.0', END) # clear the list area
for i, task in enumerate(tasks):
if task[1]:
icon = '✓'
output_format = 'done_format'
else:
icon = '✗'
output_format = 'pending_format'
self.list_area.insert(END, icon + ' ' + str(i+1) + ' ' + task[0] + '\n', output_format)
def clear_input_box(self):
self.input_box.delete(0, END)
def command_entered(self, event):
command = None
try:
command = self.input_box.get()
if command.strip().lower() == 'exit':
sys.exit()
output = self.task_manager.execute_command(command)
self.update_chat_history(command, output, 'success_format')
self.update_task_list(self.task_manager.items)
self.clear_input_box()
except Exception as e:
self.update_chat_history(command, str(e) + '\n' + self.task_manager.get_help(), 'error_format')
def start(self):
self.window.mainloop()
class TaskManager:
def __init__(self):
self.items = [
['task 1', True],
['task 2', False],
['task 3', True]
]
def get_help(self):
return 'help:\n...'
def execute_command(self, command):
if command == 'help':
return self.get_help()
elif command.startswith('add '):
self.items.append([command[4:], False])
return 'task added'
else:
raise Exception('Command not recognized')
GUI(TaskManager()).start()