# SoA Course In class practice Apr26 2022
###### tags: `Python3` `SoA` `MCUT`
Using Python programming language to design programs and complete requirements.

## Requirements:
1. Any data type (data structure)
2. class(constructors)
3. inheritance
4. exception
4.1 build-in
4.2 custom (user-defined)
7. Multi-threading
8. Input/Output (optional)

## Program design - Time Zone Converter
It program will do two things parallelly, first is convert time-zone and second is print local time.

In the first thread, it will convert time from local device to time-zone that user entered, then print converted date time. when user enter same time-zone from device, program will show the warning message (custom error handler & inheritance), and if user type the wrong format or other things, it also show warning message (system error handler).

Secnod, it just show the local date time.

Multi-thread also combined class and constructors.

### Main operations:

* thread 1, Enter the time zone that you want to convert then convert.
* thread 2, Print the local device time twice time.

### Flow chart:

* Thread 1 mainThread

st=>start: Start
e=>end: end thread

op1=>operation: convert timezone object to string
op3=>operation: Print local time
op4=>operation: Time zone converter
op5=>operation: try : convert the time


cond1=>condition: Same as local?(Custom Error)
cond2=>condition: is time zone valid?
cond3=>condition: except :
Path is correct?(OSError)

io=>inputoutput: try : input a time zone i.e. Asia/Taipei
io2=>inputoutput: print error message
io3=>inputoutput: print user entered data
io4=>inputoutput: print converted time

st->op1->io->cond1

cond1(no,bottom )->op5->cond2
cond1(yes, left)->io2
cond2(no, left)->io2
cond2(yes, bottom)->io3->io4->e

* Thread 2 printtimeThread

st=>start: Start
e=>end: end thread

op1=>operation: counter -=1

cond1=>condition: Does counter reach zero?

io1=>inputoutput: Print local time

st->cond1

cond1(no,left)->io1->op1->cond1
cond1(yes, bottom)->e

* Main program

st=>start: Start
e=>end: end thread

op1=>operation: create new thread :
thread1(params)&thread2(params)
op2=>operation: start new threads :
threads start then join

st->op1->op2->e

## Code:

#Modified by Tsun-Ping Chen (MCUT) 2022.Apr.26
import datetime
import threading
import time
import pytz     #time zone package 
from tzlocal import get_localzone   

exitFlag = 0

# define Python user-defined exceptions
class Error(Exception):
    """Base class for other exceptions"""
    pass

class SameTimeZoneError(Error):
    """Raised when the input value is too large"""
    pass

class printtimeThread(threading.Thread):
    def __init__(self, threadID, name, counter):
        threading.Thread.__init__(self)
        self.threadID = threadID
        self.name = name
        self.counter = counter
    def run(self):
        print("Starting " + self.name)
        print_time(self.name, self.counter, 2)
        print("Exiting " + self.name)

class mainThread(threading.Thread):
    def __init__(self, threadID, name):
        threading.Thread.__init__(self)
        self.threadID = threadID
        self.name = name
    def run(self):
        print("Starting " + self.name)
        convertTime()
        print("Exiting " + self.name)

def print_time(threadName, delay, counter):
    while counter:
        if exitFlag:
            threadName.exit()
        time.sleep(15)
        print ("Now is " + "%s" % (time.ctime(time.time())))
        print("%s" % threadName)
        counter -= 1

def convertTime():
    local_tz = str(get_localzone())
    try :
        zone = input("Enter time zone, like : 'Asia/Taipei' ,as Taipei time zone \n")
        if zone == local_tz :
            raise SameTimeZoneError
    except SameTimeZoneError:
            print("'\033[2;31;40mThe timezone you entered is same as your system\033[0;0m")
    dt_today = datetime.datetime.today()  # Local time
    try :
        dt_zone = dt_today.astimezone(pytz.timezone(zone))
        CZone = (dt_zone.strftime('%m/%d/%Y %H:%M'))
        print(zone + " standard time: " + CZone)
    except pytz.exceptions.UnknownTimeZoneError:     #pytz exceptions
        print(zone + "\033[2;31;0m Enter data is wrong \033[0;0m")
    finally:
        print('\033[2;30;45mYou enter is :' + zone + ' \033[0;0m')
    convertlist1 = [local_tz, zone]
    print(convertlist1,type(convertlist1))

# Create new threads
thread1 = printtimeThread(1, "Thread-1", 1)
thread2 = mainThread(2,"Thread-2")

# Start new Threads
thread1.start()
thread2.start()
thread1.join()
thread2.join()
print ("Exiting Main Thread")

## References materials:
* [Get system time zone from pytz](https://stackoverflow.com/questions/13218506/how-to-get-system-timezone-setting-and-pass-it-to-pytz-timezone)
* [Use pytz to convert timezone](https://stackoverflow.com/questions/10997577/python-timezone-conversion)
* [Class constructor](https://realpython.com/python-class-constructor/)
* [Confusion with sublcassing a threading class, and inheritance ](https://python-forum.io/thread-17340.html)
* [user defined exception](https://www.programiz.com/python-programming/user-defined-exception)
* [if-string-equals-example-code](https://tutorial.eyehunts.com/python/python-if-string-equals-example-code/)
* [convert an object to a string](https://www.adamsmith.haus/python/answers/how-to-convert-an-object-to-a-string-in-python)
* [How to Print Colored Text in Python](https://stackabuse.com/how-to-print-colored-text-in-python/)
* [Python 3 tutorials - tutorialspoint](https://www.tutorialspoint.com/python3/python_classes_objects.htm)
* [Python 3 tutorials - Geeks for Geeks](https://www.geeksforgeeks.org/python-3-input-function/)