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Python: Library Managment System -P4

June 21, 2020 2 comments


Learning : Python, DataBase, SQlite
Subject: Create Simple Library Managment System

In this Part we will work on Functions to Manage the Authors of the Books. We can enter the Authors in two ways, Even with Entering the book; such as when we are entering a New Book we can Select an Author from the list or (if the Author is not exist) we can select to Enter New Author. Or from the Author menu we can Enter New Author.

Here we are working on the Author Managment, and we will write the codes to:
Add New Authors.
Edit an Author.
Delete an Author.
Show Authors.

Here is the Author Menu with Functions Names..


We will start with Add New Author: In this Function we will ask the user to enter the Author Name then if the Author has Email or any Social Media Account, then the informations will be saved. Here is the code ..

# Authors Menu

def new_authors() :
    while True  :
        os.system('clear')
        print('\n   ====== Add New Authors ======') 
    
        author_name = input('\n   Enter the Author Name .. >  ').capitalize()
        author_email = input('   Enter the Author Email [Enter to be Empty].. >  ')

        c.execute ("select * from authors where a_name='{}'".format(author_name)) 
        result = c.fetchone()     
                 
        if (result != None) : 
             print('\n   We already have [{}] in the Auther Database. '.format(class_name)) 
        else:    
                c.execute ("INSERT INTO authors (a_name, a_email) VALUES(:a_name,:a_email)",{"a_name":author_name,"a_email":author_email})
                db_conn.commit() 
                print('\n      One Author Added ... ') 
                
                while True :
                    if input('\n   Do you want to Add any Social Media Account to this Author? [Y,N] .. >  ') in ['Y','y']: 
                        c.execute ("select max(a_id) from authors") 
                        auth_id = c.fetchone() 
                        sma_name = input('\n   Enter the Social Media Name.. > ').capitalize()
                        sma_link = input('   Enter the Social Media Link.. > ')
                        c.execute ("INSERT INTO sma (sma_name,sma_link,a_id) VALUES(:sma_name,:sma_link,:a_id)",{"sma_name":sma_name,"sma_link":sma_link,"a_id":auth_id[0]}) 
                        db_conn.commit() 
                    else:
                        break 

        if input('\n\n   Do you want to Add Another Author? [Y,N].. >  ') in ['N','n'] :
             input('\n   To Exit ... Press any key ..') 
             return


Now the Next function, Edit an Author information, here we will list down all the Authors Names and ID and the user will Enter the ID of the one to be Edited, then we will display each attribute and ask the user to Edited or just press Enter (leave it Empty) to keep the exist one. Also we will give the user the ability to Enter a new Social Media Account for the user if needed.

# Edit Author Function


def edit_authors() :
   
    os.system('clear')
    print('\n   ====== Edit Authors ======') 
    print('   The List of Authors We Have, Sorted in Alphbatic\n') 
    c.execute ("select * from authors where a_id > 0  order by a_name")     
    auth_list = c.fetchall() 
    
    # First we show all Authors so the user can select the One to be Edited.
    for auth in range (0,(len(auth_list)-1),4):
       try: 
           print('{:<3}{:<20}'.format(auth_list[auth][0],auth_list[auth][1]),end="")
           print('{:<3}{:<20}'.format(auth_list[auth+1][0],auth_list[auth+1][1]),end="")
           print('{:<3}{:<20}'.format(auth_list[auth+2][0],auth_list[auth+2][1]),end="")
           print('{:<3}{:<20}'.format(auth_list[auth+3][0],auth_list[auth+3][1]))
           
       except:
           pass # Just to avoid Index out of range.    


    edit_auth = input('\n\n   Enter the ID of the Author to Edit. [Q to Exit]  >  ')
    if edit_auth not in ['q','Q'] :
        try:
            c.execute ("select * from authors where a_id = {} ".format(int(edit_auth)))     
            auth_edi = c.fetchall()  
            # Get the Author Social Media Accounts SMA. 
            c.execute ("select * from sma where a_id = {}".format(int(edit_auth)))  
            sma_list = c.fetchall()
            print('         ID:',auth_edi[0][0])
            print('       Name:',auth_edi[0][1])
            print('      Email:',auth_edi[0][2])
            print('     Social Media:')
            for each in sma_list :  
                print('{:<11}{:  ').capitalize()
            a_email = input('   Enter the Author Email.  >  ') 
            if a_name > "" :
                c.execute("update authors set a_name = '{}' where a_id = {}".format(a_name,int(edit_auth))) 
                db_conn.commit() 
            if a_email > "" :      
                c.execute("update authors set a_email = '{}' where a_id = {}".format(a_email,int(edit_auth))) 
                db_conn.commit()      
            
            if (sma_list) != "" :
                for each in sma_list :  
                    sma_l = input('   Enter the {} Account. [D to Delete the Account]  >  '.format(each[2])) 
                    if sma_l > "" and (sma_l not in ['d','D'] ):
                        c.execute("update sma set sma_link = '{}' where a_id = {} and sma_name = '{}'".format(sma_l,int(edit_auth),each[2])) 
                        db_conn.commit() 
                    # If the user select D to Delete the SMA account. 
                    elif sma_l > "" and (sma_l in ['d','D']) :
                        c.execute ("delete from sma where sma_id = '{}' ".format(each[0]))
                        db_conn.commit()
                        print('   {} Account Deleted... '.format(each[2]))

            while True :
                    # If the user want to Add more SMA to the Author.
                    if input('\n   Do you want to Add any Social Media Account to this Author? [Y,N] .. >  ') in ['Y','y']: 
                        sma_name = input('\n   Enter the Social Media Name.. >  ').capitalize()
                        sma_link = input('   Enter the Social Media Link.. >  ')
                        c.execute ("INSERT INTO sma (sma_name,sma_link,a_id) VALUES(:sma_name,:sma_link,:a_id)",{"sma_name":sma_name,"sma_link":sma_link,"a_id":int(edit_auth)}) 
                        db_conn.commit() 
                    else:
                        break
                  
        except:
            
           print('\n   Not valid .. ')
    input('\n   To Exit ... Press any key ..')
    return



When running the code, we need to go back and forth to Show_Author function to see the effect of the Adding, Editing or Deleting functions that we are working one. Now, we will write the Delete_author Function, and as the Edit one first we will list all the Authors on the screen with there ID’s and ask the user to Enter the ID for the one to be Deleted. .. Here is the code.

# Delete an Author


def delete_authors():
    os.system('clear')
    print('\n   ====== Delete Authors ======') 
    print('   The List of Authors We Have, Sorted in Alphbatic\n') 
    c.execute ("select * from authors where a_id > 0  order by a_name")     
    auth_list = c.fetchall() 
    
    # First we show all Authors so the user can select the One to be Deleted.
    for auth in range (0,(len(auth_list)-1),4):
       try: 
           print('{:<3}{:<20}'.format(auth_list[auth][0],auth_list[auth][1]),end="")
           print('{:<3}{:<20}'.format(auth_list[auth+1][0],auth_list[auth+1][1]),end="")
           print('{:<3}{:<20}'.format(auth_list[auth+2][0],auth_list[auth+2][1]),end="")
           print('{:<3}{:  '))
    if del_auth not in ['q','Q'] :
        try:
            c.execute ("select * from authors where a_id = {} ".format(int(del_auth)))     
            auth_det = c.fetchall() 

            print('         ID:',auth_det[0][0])
            print('       Name:',auth_det[0][1])
            print('      Email:',auth_det[0][2])

            if input('\n     Are you Sure you want to Delete this Author? [Y,N].  >   ') in ['Y','y'] :
        
                c.execute ("delete from authors where a_id = '{}' ".format(int(del_auth)))
                db_conn.commit()  
                # To delete any SMA linked to this Author.
                c.execute ("delete from sma where a_id = '{}' ".format(int(del_auth)))
                db_conn.commit()
                input('\n   One Author has been Deleted... Press any Key > ')    
             
            else:
                print('\n   You Select NOT To Delete Author "{}" . '.format(auth_det[0][1]))
                input('\n   To Exit ... Press any key ..') 
        except:
            input('\n   Not valid .. ')
    return



Last Function in this part is Show Authors information, this is easy and short code, we will list down on the screen all the Authors Name, Email, SMA sorted by the Authors Name. Here is the code..

# Function to Show All Authors

def show_authors() :
    os.system('clear')
    print('\n   ====== Show Authors ======')
    print('   The List of Authors We Have, Sorted in Alphbatic\n') 
    c.execute ("select * from authors where a_id > 0  order by a_name")     
    auth_list = c.fetchall()           
    for auth in range (0,(len(auth_list))):
       try: 
           # For each Author we fetch the Social Media Accounts. 
           c.execute ("select * from sma where a_id = {}".format(auth_list[auth][0]))  
           sma_list = c.fetchall()
           print('\n     ID: {}'.format(auth_list[auth][0])) 
           print('   Name: {}'.format(auth_list[auth][1]))
           print('  Email: {}'.format(auth_list[auth][2]))
           print('  Social Media:')
           # Here we print-out the SMA for the Author.
           for each in sma_list :  
              print('{:<11}{:<13} [ {} ]'.format('',each[2],each[3]))
           print('-'*50)           
       except:
           pass     
    
    input('\n\n         ... Press any Key ..')           



Next We will work on Book Managment Menu to Add, Edit, Delete and Show Books in our Library.

[ NOTE ]
1. I am using Galaxy Tab and QPython3 App.
2. All the above codes are available in the Download Section/Page under the project name.
3. The application codes, Functions, Menus and other parts of the Application are subject of changes. In case of changes I will mention that.


:: Library Managment System ::

Part 1 Part 2 Part 3 Part 4

To Download my Python code (.py) files Click-Here




Follow me on Twitter..




By: Ali Radwani




Python: Library Managment System -P3

June 18, 2020 4 comments


Learning : Python, DataBase, SQlite
Subject: Create Simple Library Managment System

In this Part we will work on Classification Managment. As we know each book can fall in one or more subject or say ‘Classification’ then we can search for a book by it’s class, example of this, we may have classifications like: cook, computer, Health, History; also a book can have more than one classifications such as one book we gave it cook and sweet .. and so-on.

To do this we add another table to the project to hold all the Classifications and manage them. Here is the code ..

# New Table to be added.

sql_class  = "CREATE TABLE if not exists classifi_list (class_id INTEGER PRIMARY KEY AUTOINCREMENT, class_name text )"  
c.execute(sql_class)
db_conn.commit()
        
c.execute ("INSERT INTO classifi_list (class_id) VALUES(:class_id)",{"class_id":0})
db_conn.commit()

[NOTE: This code been added to the source file.]

Classification Managment: In Classification Managment we will have four Functions, and will write the codes to perform each function, also we will write the Menu Function to let the user select a function. Functions are:

1. Add New Classification.
2. Edit a Classification information.
3. Delete a Classification.
4. Show Classifications.

First: Here is the class_menu() Function, the user will have the prompt and asked to select an action or (9) to Exit.

# Classification Managment Fumction    
def class_menu(): 

    while True : 
        os.system('clear')
        print('\n   ====== LMS - Classification Managment ======')
        print('    1. Add New Classification.')
        print('    2. Edit a Classification information.')
        print('    3. Delete a Classification.') 
        print('    4. Show Classifications')
        print('    9. Exit.')
            
        user_choice = input('\n   Select the Action you want from the Menu: ')
        
        if  user_choice == '1' :
            # Function to Add New Classification   
            new_classification()

        elif user_choice == '2' : 
            # Function to Edit a Classification information.
            edit_classification()
  
        elif user_choice == '3' : 
            # Function to Delete a Classification.
            delete_classification()  

        elif user_choice == '4' : 
            # Function to Show a Classification.
            show_classification()  

        elif user_choice == '9' : 
            return 



Now, let’s start with Add New Classification. Simply we will ask the user to write a classification to be added to the Database, then we will check if it is already available in our Database, If yes then we will till the user so, or (if not available) we will add it, and will give the user the chance to add another one. If the user enter (Q or q) then we exit (Quit) from the function and return to the previous Menu.

# Function to Add New Classification

def new_classification() :
    os.system('clear')
    print('\n   ====== Add New Classification ======')  
    while True  :
        class_name = input('\n   Enter the Classification and Press Enter. [ To Exit Enter Q ].. >  ').capitalize()
        
        c.execute ("select * from classifi_list where class_name='{}'".format(class_name)) 
        result = c.fetchone()     
        if class_name not in ['q','Q']:  
            if (result != None) : 
                print('\n   We already have [{}] in the Classification Database. '.format(class_name)) 
            else:    
                c.execute ("INSERT INTO classifi_list (class_name) VALUES(:class_name)",{"class_name":class_name})
                db_conn.commit() 
                print('\n      One Classification Added ... ')
        else:
            input('\n   To Exit ... Press any key ..') 
            return
The Code
Code, Run-Time


Another Function to work on is Edit a Classification information In this one we will print-out all the Classifications we have and the user will select the one to Edit and will asked to Enter the ID number next to it. Then to Enter the New One and we will save it. Here is the code and the Out-put screen shot. To display all classifications on the screen we will use this code..

# Code to display the classifications on the screen

# First we list down all classifications.
    c.execute ("select * from classifi_list where class_id > 0  order by class_name")     
    class_list = c.fetchall()           
    for cla in range (0,(len(class_list)-1),4):
       try: 
           print('{:<3}{:<20}'.format(class_list[cla][0],class_list[cla][1]),end="")
           print('{:<3}{:<20}'.format(class_list[cla+1][0],class_list[cla+1][1]),end="")
           print('{:<3}{:<20}'.format(class_list[cla+2][0],class_list[cla+2][1]),end="")
           print('{:<3}{:<20}'.format(class_list[cla+3][0],class_list[cla+3][1]))
           
       except:
           pass 

[NOTE: We use the try: except to avoid any (index out of range) errors.]

Code
Code, Run-time



Next we will work on the Delete a Classification, Deleting may effect on some Books that uses that classification, so we need to till the user to confirm Deleting. Also we will use the same code to list down all the classifications and ask the user to enter the ID of the one to-be Deleted. Here is a part of the code to Delete a classification..

# Part of the code .. 

del_class = input('\n\n   To Delete a Classification Enter it''s ID number [Q To Exit]  > ')

if del_class not in ['Q','q'] :
    c.execute ("select * from classifi_list where class_id = '{}' ".format(int(del_class))) 
    c_to_del =  c.fetchone()[1]     
    print('\n   Are you sure you want to Delete "{}" Classification? '.format(c_to_del))     
    print('   This action may effect on books has this Classification.') 
    user_approve = input('\n   If you are sure to Delete "{}" Press Y or N: > '.format(c_to_del))  
    if user_approve in ['y','Y'] : 
        c.execute ("delete from classifi_list where class_id = '{}' ".format(del_class))
        db_conn.commit() 
        input('\n   One Classification has been Deleted... Press any Key > ')    
    else: 
        input('\n\n   You Select NOT to Delete the "{}" Classification, Press any key to go back.. '.format(c_to_del))

    if input('\n   Do you Want to Delete Another Classification? [Y,N] > ') in ['n','N'] :
         return 
else:
    input('\n   You Select to Exit .. Press any Key > ')
    return   
    
The Code Code Run-Time



Last Function to work in this post is Show Classifications the function we will list down all the Classifications on the screen. Very easy one, here it is

# Show Classification Function

def show_classification():      
    os.system('clear')
    print('\n   ====== Show Classification ======')
    print('   The List of Classifications We Have, Sort in Alphbatic\n') 
    c.execute ("select * from classifi_list where class_id > 0  order by class_name")     
    class_list = c.fetchall()           
    for cla in range (0,(len(class_list)-1),4):
       try: 
           print('{:<3}{:<20}'.format(class_list[cla][0],class_list[cla][1]),end="")
           print('{:<3}{:<20}'.format(class_list[cla+1][0],class_list[cla+1][1]),end="")
           print('{:<3}{:<20}'.format(class_list[cla+2][0],class_list[cla+2][1]),end="")
           print('{:<3}{:<20}'.format(class_list[cla+3][0],class_list[cla+3][1]))
           
       except:
           # just in case error, pass and do nothing.
           pass        
    input('\n\n         ... Press any Key ..') 
Code
Code Run-time




What’s Coming In coming post, we will write the Functions to Manage the Authors.

[ NOTE ]
1. I am using Galaxy Tab and QPython3 App.
2. All the above codes are available in the Download Section/Page under the project name.
3. The application codes, Functions, Menus and other parts of the Application are subject of changes. In case of changes I will mention that.




:: Library Managment System ::

Part 1 Part 2 Part 3

To Download my Python code (.py) files Click-Here




Follow me on Twitter..




By: Ali Radwani




Python: Library Managment System -P2

June 16, 2020 5 comments


Learning : Python, DataBase, SQlite
Subject: Create Simple Library Managment System

The Data: In the Part-1 we Talk about the Entities that we will create and about the Data we will collect (Fields). So here we are writing them again and we will add classification for each book :
Books Entity: Book Name, Book Author, Date of publish, Edition Number, Book classification number.
Author Entity : Author name, Author Nationality, email, SMA (social media account).
From the Author information we can see that we need to define a new Entity to hold the SMA.
SMA Entity: SMA Name, SMA Link.
Class Entity: class Name.
Here is each entity and field :
book:

  • b_id integer PK
  • b_name text,
  • b_a_id integer,
  • b_isbn text,
  • b_dop text,
  • b_ed integer

author:

  • a_id integer PK
  • a_name text
  • a_email text

sma:

  • sma_id integer PK,
  • a_id integer,
  • sma_name text,
  • sma_link text

class:

  • class_id integer PK
  • class_name text
  • Now we will write the code to create the Database and set a connection

    # create the Database and set a connection

    import sqlite3, os

    # Create the data-base & name it as LMS.
    db_conn = sqlite3.connect ("LMS.db")

    # set the connection.
    c = db_conn.cursor()

    Now we will create the tables..

    # Function to create the tables

    def create_tables_() :
    # to create tables.
    sql_books = "CREATE TABLE if not exists books (b_id INTEGER PRIMARY KEY AUTOINCREMENT, b_name text, b_a_id integer,b_isbn text, b_dop text, b_ed integer)"

    sql_author = "CREATE TABLE if not exists author (a_id INTEGER PRIMARY KEY AUTOINCREMENT ,a_ name text, a_email text )"

    sql_class = "CREATE TABLE if not exists classifi_list (class_id INTEGER PRIMARY KEY AUTOINCREMENT, class_name text )"



    sql_b_class = "CREATE TABLE if not exists b_class (b_class_id INTEGER PRIMARY KEY AUTOINCREMENT, b_id integer, class_id integer )"

    sql_sma = "CREATE TABLE if not exists sma (sma_id INTEGER PRIMARY KEY AUTOINCREMENT, a_id integer,sma_name text, sma_link text)"


    c.execute(sql_books)
    db_conn.commit()

    c.execute(sql_author)
    db_conn.commit()

    c.execute(sql_class)
    db_conn.commit()


    c.execute(sql_b_class)
    db_conn.commit()

    c.execute(sql_sma)
    db_conn.commit()

    input('\n .. LMS Tables created.. Press any key .. ')

    After creating the tables, and to make sure that AUTOINCREMENT of Primary key will run we need to have a number in each PK field, to do that we will add a 0 (Zero) record to each table. Here is the code to do it ..

    #Function to Insert the Zero Record

    #Function to Insert the Zero Record.
    def insert_record_0():

    c.execute ("INSERT INTO books (b_id) VALUES(:b_id)",{"b_id":0})
    c.execute ("INSERT INTO authors (a_id) VALUES(:a_id)",{"a_id":0})
    c.execute ("INSERT INTO classifi_list (class_id) VALUES(:class_id)",{"class_id":0})

    c.execute ("INSERT INTO b_class (class_id) VALUES(:class_id)",{"class_id":0})
    c.execute ("INSERT INTO sma (sma_id) VALUES(:sma_id)",{"sma_id":0})

    db_conn.commit()

    input('\n ...Dummy records been Inserted .... Press any key .. ')

    The above functions create_tables_() and insert_record_0() will be run only one time to create the tables, and insert record number ZERO. During the programming and coding we may need to delete the DataBase and re-created again, in that case we run the both functions again.

    Create the Menus
    As we side, each Entities will have three Main Functions [Add, Edit, delete ad search]. Let’s start with Main Menu.

    Main Menu Code
    Main Menu Run-Time
    Book Menu, Code
    Book Menu, Run-Time
    Author Menu, Code
    Author Menu, Run-Time
    Classification Menu, Code
    Classification Menu, Run-Time
    Search Menu, Code Search Menu, Run-Time

    What’s Coming In coming post, we will write the Functions to Manage the Authors and Classifications.

    [ NOTE ]
    1. I am using Galaxy Tab and QPython3 App.
    2. All the above codes are available in the download section/page under the project name.
    3. During the progress of the project, we may need to Add, Edit or delete any Tables, Fields, Menus or Functions that we had already finished.

    :: Library Managment System ::


    Part 1 Part 2

    To Download my Python code (.py) files Click-Here


Follow me on Twitter..


By: Ali Radwani

Python: Library Managment System -P1

June 14, 2020 5 comments


Learning : Python, DataBase, SQlite
Subject: Create Simple Library Managment System

Details: The project is to Plann, design and builed a simple Library Managment System LMS (For Books), the main Functions in the system are: (In this Version 1)

  • Add New Book.
  • Edit an exsit Book.
  • Delete a Book.
  • Search.

Planning: In this step we need to sit with the Business owner to identify the problem and plann the project. Since we will work as Fullstack (mean we will do every thing) and this is a training session project, we will be the Business owner of the project and will talk about the problem.

The Problem: In a very simple way, we have some Books and we want a System to store the books in a way that we can retrieve it’s basic information such as Title, Author, Subject and other information about it. Also we need to do some basic search to get statistics about our Library.

Data Gathering: First we need to define the Data we want to stoe, as we are talking about a simple Books Library System we can predict this very easily by looking to a book that we have and write-dowan the keys part of the book we want to store.
In this project we have three main Entities : Books, Authors, Borrowers. In this version (V.01) of the project we will NOT cover the borrowing functionality. So we will store the following data:

Books Entity: Book Name, Book Author, Date of publish, Edition Number, Book classification number.

Author Entity : Author name, Author Nationality, email, SMA (social media account).
From the Author information we can see that we need to define a new Entity to hold the SMA.
SMA Entity: SMA Name, SMA Link.

To Manage our System we will write Four main functions for each entity:
ADD, Edit, Delete and search.

Part 2: In Part-2 we will create the tables (The Entities), Insert the Zero-Row and create the Main Menu for each Entities.


:: Library Managment System ::

Part 1 Part 2 Part 3 Part 4



To Download my Python code (.py) files Click-Here




Follow me on Twitter..




By: Ali Radwani




Python: Drawing Math Equations



Learning : Python and Math
Subject: Python Project to Draw a Math Equations

In the past week or so I saw a tweet from @matthen2 it was about drawing half circles on 99 points, the 99 points was distributed on a hidden circle, each line (or half circle) connecting x (a point on the circle) and it’s double, so point num 2 is connected to P num 4; (P3 to P6, P4 to P8, …) and so-on

This inspired me to write a Python app (code) to perform same action. Then I just upgrade the idea to draw any mathematical Equation. (Lets say simple mathematical Equations)

In our project, the user will enter the number of points and the starting circle radius, also I fond that we can do more by reducing the circle radius after each point, so i add this to the project.

Coding: We will write a function to collect the points in a list as [x,y], and returns the list. Then we pass each two points of (x1,y1) and (x2,y2) to another Function to draw a line between those points. In this version we will write the Equations as hard-code in our project.

So First Function will be the get_points() here the systems will ask the user to Enter some variables. We will collect the number of points P, the raidus of the circle circumference that points will be distributed On it’s, also we will ask the user if circle radius is fixed or decreased by a given factor.
Using mathematics we know that a circle has 360degree, so if we divide 360 over P we will have (if we can call it) the arc_angle. .. Here is the code for the function …

# Function to collect the x,y points

def get_points() :
  p = int(input('  Enter number of Points:  ')) # number of points.

  arc_angle = 360 / p
  circle_r = int(input('  Enter the Cricle Radius: ') )  
  fix_r = int(input('  Enter a number to reduce the Radius:'))
  
  #To return the x,y list of the points that we want to connect. 
  p_list = []
  t.goto(0,0)
  t.setheading(-90)
  
  for p in range (0,p+1) :

    t.goto(0,0)
    t.forward(circle_r)
    nx = t.xcor()
    ny = t.ycor()
  
     # If the user want to reduce the radius.
    circle_r = circle_r - fix_r
    p_list.append([nx,ny])
    t.right(-arc_angle)

  return p_list



By now, we have a list of points [x,y], and we will passing two points to another function def draw_line(x1, y1, x2, y2): to draw a line between the points. Very simple and easy Function …

# Function to draw a line

def draw_line(x1, y1, x2, y2):
  
  t.goto(x1,y1)
  t.pendown()
  t.goto(x2,y2)
  t.penup()


Now the tricky part, How to select the points?. To do this we assume we have an Equation (e1) and if we got any errors like (division by zero, or out of index) we will apply another Equation (e2), e1 and e2 will be hard-coded and each time we need to change it and run the application again to see the result. And to draw a line between the points based on e1 and e2 we will run a for loop …. Here is the code ..

# drawing the equations 

 

for d in range(len(p_list)-1) :
  
  e1 = d * 2
  e2 =  abs( len(p_list) - (d*2))

  try:
    draw_line(p_list[d][0], p_list[d][1],p_list[e1][0], p_list[e1][1])
  except:
    if e1 > len(p_list) :
      draw_line(p_list[d][0], p_list[d][1],p_list[e2][0], p_list[e2][1])


Here is some output




This is the end of this project, Do we need any upgrading in any part of it?



To Download my Python code (.py) files Click-Here




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By: Ali Radwani




Python : Triangle Parameters



Learning : Python to Draw a Triangle
Subject: To get the Parameters of a Triangle

A week ago I start helping a friend in a mathematics geometric to draw a Triangle from Two points that represent the The Hypotenuse of a Triangle, then I deside to write a python project to Draw a triangle based on two given points (x1,y1) and (x2,y2) and to print it’s parameter (other sides and angles). We will use the Trinket.io as a Python interrapter and will draw with turtle library.

Project Details: The system will ask the user to Enter the coordinates of Two points To draw a Right Angle Triangle. In our Triangle, we will call the (x1,y1) as Point A, and (x2,y2) as Point C. From our starting poins we can calculate the distance between point A and point (B), also the length of Hypotenuse and the angels in the Triangle.

So, What we have:

tri_opposite = abs( y2 – y1 )

tri_adjacent = abs( x2 – x1 )

From a mathimatics triangle formula we know that:

Opposite^2 + Adjacent^2 = Hypotenuse^2

where: x^2 = square(x)

So:

tri_hypo = tri_opposite**2 + tri_adjacent**2

tri_hypo = math.sqrt(tri_hypo)

tri_hypo is the distance between point A and Point C (the opposite
side of the right angle)

Now the Angels:
As we know that in a triangle the summation on all inside angles is 180deg, and in a Right Triangle we will have a one fixed 90 degree angle (ABC), so the first thing we will work on calculating the Opposite angle (BAC).

From a Triangle math:

tri_opposite = abs( y2 – y1)

tri_adjacent = abs(x2 -x1)

the_deg (BAC) = inverse tan for (tri_opposite / tri_adjacent)

# get the inverse of Tan

the_ang = math.degrees(math.atan(the_deg))

Now, lets do some coding ..

First thing we will import two libraries turtle and math, also we will do some setting for our turtle. … Here is the code ..

# Turtle setting


import turtle, math
# turtle_setting 
t = turtle.Turtle()
t.penup() 
t.shape("non")
#t.speed(9)
t.speed('fastes')
#t.visible = False

t.hideturtle()



Then we will write a code to draw a ‘Gray’ coordinates cross lines for our project. Here is the code for it ..



def the_cross() :
     # To draw the cross represents the coordinate.
    t.penup()
    t.pencolor('gray') 
    t.goto(-200,0)
    t.setheading(0)
    t.pendown()
    t.forward(400)
    t.penup()
    t.goto(0,200)
    t.setheading(90)
    t.pendown()
    t.forward(-400)
    t.penup()
    t.goto(2,0)
    t.pendown()
    t.circle(2)
    t.penup()
    t.goto(0,0)
    t.setheading(0)

# calling the function 
the_cross() 


Now we will write the main function code, First we will ask the user to enter the x,y for two points, then we will do our calculations to get other Triangle parameters and angles, finally we will draw the Triangle. .. Here is the code..



def draw_triangle(x1, y1, x2, y2) :

# draw the Triangle. 
    style = ('Courier', 20)   # font style.
    t.penup()
    t.goto(x1,y1)
    t.setheading(0)
    t.pendown()
    t.circle(1)  # To draw small circle on point A.
    t.write('A',font = style)  # To write A next to the point.
    t.forward((x2-x1))
    x3 = t.xcor() # here is the x for point B
    y3 = t.ycor() # here is the y for point B

    t.right(-90)
    t.forward((y2-y1))
    t.write('C',font = style)  # To write C next to the point.
    t.goto(x2,y2)
    t.setheading(0)
    t.pendown()
    t.circle(1)  # To draw small circle on point C.
    t.penup()
    t.goto(x3,y3)
    t.pendown()
    t.circle(1)  # To draw small circle on point B.
    t.penup()
    t.setpos(x3-15,y3-15)
    t.write('B',font = style)  # To write B next to the point.


    # To calculate the angle of BAC using Triangle Math Equations. 
    tri_opposite = abs( y2 - y1)
    tri_adjacent = abs(x2 -x1)
    the_deg = tri_opposite /  tri_adjacent

    # get the inverse ot Tan using Triangle Math Equations.  
    the_ang = math.degrees(math.atan(the_deg)) #atan(x) is the inverse of math Tan function.

    t.goto(x1,y1)

    # To correct the rotation angle based on it's coordinates.
    if (x1 > x3) and (y2 > y1) :
      rotation = the_ang - 180

    elif (x1  y1):
      rotation =  360 - the_ang

    elif (x1 > x3) and  (y2 < y1) :
      rotation =  180 - the_ang

    elif (x1 < x3) and  (y2 < y1) :
      rotation =   the_ang - 360

    #t.right(rotation)
    #t.pendown()
# From using Triangle Math Equations, we know that Hypotenuse^2 = Opposite^2 + adjacent^2.  
    
    tri_hypo = tri_opposite**2 + tri_adjacent**2
    tri_hypo = math.sqrt(tri_hypo)
    t.right(rotation)
    t.pendown()
    t.forward(tri_hypo)
    t.penup()

    print('\n  The Triangle Information:')
    print('  Point A= ({},{})'.format(x1,y1))
    print('  Point B= ({},{})'.format(x3,y3))
    print('  Point C= ({},{})'.format(x2,y2))
    print('  Adjacent',tri_adjacent)
    print('  Opposite',tri_opposite)
    print('  Hypotenuse',tri_hypo)
    print('  Angle: ABC = 90')
    print('  Angle: BAC = ',the_ang)
    print('  Angle: ACB = ',180 - the_ang - 90)


Finally, we need to call the function and pass the two point to it, to do this first we will ask the user to Enter the Two Points and we will make sure that the points are not the same.. Here is the code ..

# calling the draw_triangle function ..
 
print('\n   To draw the Triangle you need to Enter Two Points as X,Y for each one.')
x1 = int(input('   Enter x for First point: '))
y1 = int(input('   Enter y for First point: ')) 
x2 = int(input('   Enter x for Second point: '))
y2 = int(input('   Enter y for Second point: ')) 
 
if (x2==x1) or (y2==y1) : 
   print('  Your Points are not valid, (x1,x2) or (y1,y2) can't be equal ')
else :
   draw_triangle(x1, y1, x2, y2)




To Download my Python code (.py) files Click-Here




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By: Ali Radwani