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Posts Tagged ‘radwani’

Python and Lindenmayer System – P1

October 31, 2019 3 comments


Learning : Lindenmayer System P1
Subject: Drawing with python using L-System

First What is Lindenmayer System or L-System? L-System is a system consists of an alphabet of symbols (A, B, C ..) that can be used to make strings, and a collection of rules that expand each symbol into larger string of symbols.

L-system structure: We can put it as Variables, Constants, Axiom, Rules

Variables (V): A, B, C …
constants : We define a symbols that present some movements, such as ‘+’ mean rotate right x degree, ‘F’ mean move forward and so on ..
Axiom : Axiom or Initiator is a string of symbols from Variable (V ) defining the initial state of the system.
Rules : Defining the way variables can be replaced with combinations of constants and other variables.

Sample:
Variables : A, B {we have two variables A and B}
Constants : none
Axiom : A {Start from A}
Rules : (A → AB), (B → A) {convert A to AB, and convert B to A}

So if we start running the Nx is the number the time we run the rules (Iteration).
N0 : A
N1 : AB
N2 : AB A
N3 : AB A AB
N4 : AB A AB AB A
N5 : AB A AB A AB A AB .. an so-on
So in this example after 5 Iteration we will have this pattern (AB A AB A AB A AB)

In this post we will write two functions, one to generate the pattern based on the Variables and Rules we have. Another function to draw the pattern using Python Turtle and based on the Constants we have within the patterns.

The constants that we may use and they are often used as standard are:

F means “Move forward and draw line”.
f means “Move forward Don’t draw line”.
+ means “turn left by ang_L°”.
− means “turn right ang_R°”.
[ means “save position and angle”.
] means “pop position and angle”.
X means “Do nothing”

and sometime you may add your own symbols and and rules.

First Function: Generate the Pattern will take the Axiom (Start symbol) and apply the rules that we have (as our AB sample above). The tricky point here is that the function is changing with each example, so nothing fixed here. In the coming code i am using only one variable F mean (move forward) and + – to left and right rotations. Other patterns may include more variables. once we finished the function will return the new string list.

Generate the Pattern

# Generate the patern
def l_system(s) :

new_s = []

for each in s :

if each == ‘F’:

new_s.append(‘F+F+FF-F’)

else :

new_s.append(each)

return new_s



The second function: Draw the Pattern will take the string we have and draw it based on the commands and rules we have such as if it read ‘F’ then it will move forward and draw line, and if it reads ‘-‘ then it “turn right ang_R°”.
here is the code ..

Draw the Pattern
def draw_l_system(x,y,s,b,ang_L,ang_R):

cp = [] # Current position

t.goto(x,y)

t.setheading(90)

t.pendown()

for each in s:

if each == ‘F’ :

t.forward(b)

if each == ‘f’ :

t.penup()

t.forward(b)

t.pendown()

elif each == ‘+’:

t.left(ang_L)

elif each == ‘-‘:

t.right(ang_R)

elif each == ‘[‘:

cp.append((t.heading(),t.pos()))

elif each == ‘]’:

heading, position = cp.pop()

t.penup()

t.goto(position)

t.setheading(heading)

t.pendown()

t.penup()


Now we will just see a one example of what we may get out from all this, and in the next post P2, we will do more sample of drawing using L-System.


In the image bellow, left side showing the Rules, angles and iterations and on the right side the output after drawing the patters.



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


Python: Date Validation Function

October 29, 2019 1 comment


Learning : Date Validation Function
Subject: Dll’s and Function

In late of 90’s, I start writing DLL files, Dll file or Dynamic Link Library is a file that contain instructions or function that can be used and reused with/by other applications. So if we have a function that we keep using it in most of our programs then we write it in a dll file and re-call it any time we want to.

Writing a function that can be added to a Dll file and will be used by all the team is not a simple as it appeared to be, Dll files often contains more than one functions so we may find ten or twenty functions in there most are related so a DLL file need to be a very well documented and each function has it’s own comments, variables, version number and summary of its task and what it will return back.

In this post we will write Python code for a date validation function, the function will take one argument and will return values as :
1. Function will return False and error message if the passed argument is not a valid date.
2. Function will return True and the date if the date is valid.

Date Validation Function:

# Date validation function
# Variables: This function will take one argument as a user input date.
# Returns: This dunction will return Fals and error_message each itme the user enter a not valid date.
# The functin will return True and the date in case it was correnct.
# The function will returns value as a list.

def valid_date(my_date):

# get the separator

the_separator = []

for each in my_date :

if not each.isdigit():

the_separator.append(each)

# If the user inter other that two separators then the date is invalid.

if len (the_separator) != 2 or (the_separator[0] != the_separator[1]):

error_message = “Date is not valid.”

return False, error_message

d,m,y = (my_date.split(the_separator[0]))

if not d.isdigit() or (int(d) > 31 or int(d) < 1 ):

error_message = ‘Day must be number and between (1-31).’

return False, error_message

if not m.isdigit() or (int(m) > 12 or int(m) < 1 ) :

error_message= ‘Mounth must be number and between (1-12).’

return False, error_message

if not y.isdigit() or len(y) != 4 or int(y) < 1:

error_message = ‘Year must be a 4-digit positive number. ‘

return False, error_message

# convert the days and month to two digits numbers

if len(d) == 1: d =’0′ + d

if len(m) == 1: m =’0′ + m

my_date = d + ‘/’ + m + ‘/’ + y

return True, my_date


So now if we want to call the function and pass the user input to it then examine the returns, we may use the While loop as here..


vd=[False,0]

while vd[0] == False :

my_date = input(‘\n Enter the date as dd/mm/yyyy :’)

vd = valid_date(my_date)

if not vd[0] : print(‘ ‘,vd[1])

print(“\n we have a valid date, it is .. “, vd[1])


… Have fun …



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





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Python: Drawing Shapes

October 27, 2019 Leave a comment


Learning : Drawing Shapes
Subject: New shapes function

To Draw a Square shape, we need to know the width ( W ) of the square side, and then we draw a line and moving in 90 degree and drawing another line and so on until we finished the 4 side of the square. In the same principle if we want to draw a triangle (equilateral one), we need to know length of its sides and in mathematics we know that in equilateral triangles the angles (corners) are 120 degree, so we draw a line and move in 120 degree and drawing another two sides.

In coming code, we will write a general function in Python to pass the number on sides we want to draw (triangle =3, Square=4,Pentagon = 5, Hexagon =6 .. and so on), the width (size) of the shape and the position (x,y) of the first angle or point.

The Codes:

def d_shape(s_heads,w,x1,y1):

t.goto(x1,y1)

# To get t.right angle

rang = 360 / s_heads

t.pendown()

for x in range (s_heads +1) :

t.forward(w)

t.right(-rang)

t.penup()



Results after using the new function we can pass any number of sides and the function will draw the shape, here are a sample execution of it. .. .. Click to enlarge ..




Now if we call the function number of times equal to it’s heads what we will get ? let’s see . .. Click to enlarge ..


And take a look when we set the numbers to 20. .. Click to enlarge ..



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Python: Random Squares

October 24, 2019 Leave a comment


Random Squares Art
Subject: Python, Graphics and simulation

In This project say we have a Square (10 x 10 cm) the square has four corners labeled as (a, b, c, d) as in figure i.



then we select a random corner (c or d) [assume it is c] then we select an angle (ang) of rotation between (10, 45), and we draw another square positioning (a) on the (c) and rotating it with (ang) anticlockwise as figure ii.



Now if we repeat this two steps ..
S1. Selecting a random corner (c or d).
S2. Selecting a random rotation angle between (10, 45). and draw the square.
let’s see what we may have as a random art generator.




Python Code for Random Squares Art
Codes to select corner (c or d)
def select_c_or_d():

if random.randrange(0,2) == 0 :

x = cdpos[0][0]

y = cdpos[0][1]

else:

x = cdpos[1][0]

y = cdpos[1][1]

t.setheading(0)

t.right(random.randrange(rotmin,rotmax)*f)


Codes to draw the Square (c or d)
def d_square(w,x1,y1):

t.goto(x1,y1)

t.pendown()

t.forward(w)

t.right(-90)

t.forward(w)

# save corner c position

cdpos.append([t.xcor(),t.ycor()])

t.right(-90)

t.forward(w)

# save corner d position

cdpos.append([t.xcor(),t.ycor()])

t.right(-90)

t.forward(w)

t.penup()



I notes that if we increase the number of Squares, we start to have some interesting results.

.. Have Fun ..



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




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Python Project: Ant Escaping Path

August 29, 2019 Leave a comment


Python simulation project
Python, Graphics and simulation

In this project we assume that we have a square pad and we put an ant in the center of this pad, we let the ant to walk, once it reach any eadgs of the square we move it with our hand to the middle again, say we doing this for x times and each time we colored the ant foots with gray level (light to dark) color. Our project is to write a code to simulate this task (ant movement). 

Enhancement: Here are some enhancement ideas:
1. We can use the Pi or Golden Ratio for the variables.
2. Also we can set a memory facto so with each time we move the Ant to the center the memory will increase so it may use the same path.
3. For the memory, we can set a position (x,y) as a food, and each time it reach the food it’s memory will increase.


The Code

# Create in 27/8/2019 .

import turtle
import random

screen = turtle.Screen()
screen.setworldcoordinates(-700,-700,700,700)
screen.tracer(5)

t1=turtle.Turtle()
t1.speed(0)
t1.penup()

# colors varibles
# r=240, g=240, b=240 is a light gray color

r=240
g=240
b=240
t1.pencolor(r,g,b)

cf = 3 # color increasing factor
ff = 0 # ant forward moving factor
#screen.bgcolor(“black”)

def rand_walk(x,the_t):

the_t.pendown()

# The color will be darker each time

the_t.pencolor(r-(x*cf),g-(x*cf),b-(x*cf))

the_t.forward(20+(ff*x))

def ant_walk ():

x = 1

while x < 7 : # Moving the Ant to the center 7 times

rand_walk(x,t1)

if random.randrange(1,100) %2:

t_ang = random.randrange(10,45)

t1.right(t_ang)

else:

t_ang = random.randrange(10,45)

t1.left (t_ang)

# if the ant reach the square boards then we move it to the center.

if (t1.xcor() > 650 ) or (t1.xcor() 650 ) or (t1.ycor() < -650 ):

t1.penup()

t1.goto(0,0)

x = x + 1

# Calling the Function
ant_walk()


Here is an GIF file



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




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Python: Orders Manager P4

August 27, 2019 Leave a comment


Learning : Orders Management System using Python and Pandas
Subject: File Exists and Adding new Record

In the last post of our system, we develop the file_exists function, the function is checking if the file not exists then will create ond and enter a dummy data. Now we need to add a code to the application body that call this function and if the file exists the application will run without applying the or creating any file. Here is the code in the application body:

Header here

if file_exists() != ‘exit’ :

# calling the menu

user_enter = the_menu()

”’
Validation: If the user enter any thing else than numbers
or (q for quit) nothing will happen.
”’

while user_enter !=’q’ or ‘Q’ :

if user_enter in [‘q’,’Q’] :

print(‘\n You select to Exit the application.’)

save_it = input(‘\n Do your want to save your work/changes [y or n] ? ‘)

if save_it in [‘y’,’Y’]:

save_the_df (df)

break

elif user_enter not in [‘1′,’2′,’3′,’4′,’5′,’6′,’7′,’8′,’9’] :

user_enter = the_menu()

else:

user_choice(user_enter)

user_enter = the_menu()


In this post we will talk about the Adding new record function, since we may start from new file we need to enter some records in our data file. Here is the def add_new_record() that will help us to enter our data.

Add New Record Function

def add_new_record(old_df):

clear() # To clear the terminal.

app_header()

# First we will fetch the columns from the df

col_list = []

for each in old_df.columns :

col_list.append(each)

print(col_list)

# Get max id and increase it by 1

next_id = old_df[‘order_no’].max()+1

new_row={}

# let user enter the new record.

print(‘\n Enter the data for each field then press Enter.\n’ )

print(‘ If you just press Enter NaN will be entered.’)

for each in col_list:

if each !=’order_no’:

print(‘ Enter data for ‘,each)

new_row.update({each:(input(‘ : ‘))})

new_row.update({‘order_no’:next_id})

old_df = old_df.append([new_row])

for each in col_list :

if (old_df.loc[old_df[‘order_no’] == next_id, each][0]) ==”:

(old_df.loc[old_df[‘order_no’] == next_id,[each]]) = float(‘NaN’)

print(‘\n New Record added successfully..\n’)

# print out last 5 rows to show the new record.

print(‘\n The new record in the df..\n ‘,old_df.tail(5))

global df # Reset the df as global variable

df = old_df

input(‘\n\n\n\n ** Press any key to continue .. . . ‘)


In the coming post, we will work on the date validation function also the user choice loop so we can run the application and test it.



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Python: Orders Manager P3

August 25, 2019 Leave a comment


Learning : Orders Management System using Python and Pandas
Subject: Data File and Adding new Record

In This system and once the user run the application we will check if the Data file exists or not. If the file exists then the system will run, otherwise the application will guide the user to some questions to create the new file. Then we will talk about adding new records to our file.

First time run: Each time we run the application the system will chick for the file, at this version we will have only one data file we will call it “orders_dataframe.csv” if the file exists the application will continue and the file will be loaded automaticly, if not, then the first choice of our menu will be called. Function called “create_file()” will run, we will inform the user that the file is not there and if he want to create a new file. If the user select Yes, the file will be created and a dummy row (id = 0) will be added. If the user select No, we will show a message then if any key pressed the system will quite. .. Let’s see the code ..

File Exists check point
def file_exists():

# Check if the data file not exists create one

if not (os.path.exists(‘orders_dataframe.csv’)):

no_file =’o’

while no_file not in [‘y’,’Y’,’n’,’N’]: # Validation for user input

clear() # To clear the terminal.

app_header()

no_file = input(‘\n The file ”orders_dataframe.csv” is not exists, Do you want to create new one: [ y , n ] ‘)

if no_file in [‘y’,’Y’]: # Validation for user input

create_file() # Call the function create_file

return

elif no_file in [‘n’,’N’]: # Validation for user input

print(‘\n You select not to create a data file, so the system will Exit. ‘)

input(‘\n\n Press any key …’)

return ‘exit’


Validation:
To keep asking the user for his input until he enters one of [ y,Y,n,N]

while no_file not in [‘y’,’Y’,’n’,’N’]:

no_file = input(‘\n The file ”orders_dataframe.csv” is not exists, Do you want to create new one: [y,n] ‘)


Last, I am thinking to add a header for our app, so this header will be at the top of all out screens. Here it is ..

Application Header
def app_header():

print(‘\n ********************************’)

print(‘ ** Orders Managment System **’)

print(‘ ** App V.08-19 **’)

print(‘ **********************************\n’)


In the next post we will look at the Validation on the File Exists check and create file function, also first row added to our dataframe.



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Python: Orders Manager P2

August 22, 2019 Leave a comment


Orders Managment System
Subject: Main Menu and creation of the data file – P2

First thing we will talk about the menu, in this post we will cover the Main Menu and the user choice. Also we will add some validation.

Main Menu: Here is a list of what we will have in the main menu with some descriptions for each choice.
Load File: We will name the file as “orders_data.csv” so once we start the application the system will check if the file exist or not, if Yes then the application will load it automatically as DataFrame (df) if not thats mean you are running the app for the first time, so we will go through file creating process.

Show Data: In this option we will have another sub menu page having:
1. Show all data.
2. Show sample data.
3. Show last 5 records.

Sort: Here we will have sorting as columns that we have, the user will select a column.

Search: We can here search for an order by Date, Price, Quantity or details, also we will do groping for the data.
Missing Data: To show us how many missing data we have so we can fill them.
Add New Order: To add new order to the system.
Edit a Record: To Edit/change a record.
Delete a Record: To delete a record from the DataFrame.
Save: To save what ever you do to the DataFrame.

The Main Menu

def the_menu ():

print(‘\n ::—–{ The menu }—-::’)

print(‘1. Create New csv File’)

print(‘2. Show Data’)

print(‘3. Sort.’)

print(‘4. Search.’)

print(‘5. Missing Data’)

print(‘6. Add New Record.’)

print(‘7. Edit a record.’)

print(‘8. Delete a Record.’)

print(’9. Save the File.’)

return input(‘\n Select from the menu (”q” to quit): ‘)


Main while loop: In the application body we will use a while loop to control the user input and run the function he select. Unlike what we did In the zoo managment system, we will add a validation on the user input as:

Validation:
1. If the user enter any thing else than numbers (1 to 9) or ([q – Q] for quit) nothing will happen.
2. If the user select (q to quit) then we will ask if he want to save before Exit.



Here is the code …

Main while loop
# calling the menu
user_enter = the_menu()

”’
Validation: If the user enter any thing else than numbers
or (q for quit) nothing will happen.
”’
while user_enter !=’q’ or ‘Q’ :

if user_enter in [‘q’,’Q’] :

print(‘\n You select to Exit the application.’)

save_it = input(‘\n Do your want to save your work/changes [y or n] ? ‘)

if save_it in [‘y’,’Y’]:

save_the_df (df)

break

elif user_enter not in [‘1′,’2′,’3′,’4′,’5′,’6′,’7′,’8′,’9’] :

user_enter = the_menu()

else:

user_choice(user_enter)

user_enter = the_menu()


Here is a screen shot for the code..




In this post we cover the Main Menu and the main while loop we need to call the functions, in the coming post we will create the data file and Adding new record.



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Python: Orders Manager P1

August 20, 2019 Leave a comment


Orders Managment System
Subject: Outlines – P1

In last several posts we develop a Zoo Managment System [Click to Read]. We try to use our skills in python and pandas to work with DataFrame and developing easy app that reading and writeing a csv file. We will use the same principle and re-use most of it’s functions to write our new coming system.

The Story: I don’t think that there is any person using the web without using at least one of the online shopping sites, personally; I am using three sites. In coming posts we will work on Orders Managment System (OMS) to track our orders.

General Enhancement In the Zoo application we did not use any validation or try … Exceptions blocks, but this time we will use a range of validations over the user input starting from the menu until asking if the user want to save shange before he Quit. Using validations will make the code (or make it looks like) complicated, so I will use lots of comments to describe some codes.

Validation Example ..
In our Date entry, we will inform the user that we want the date as DD-MM-YYYY , then if the user enter any thing not logic (not a date) or say he enter “3/8-2019” our validation will convert that to “03-08-2019”.


OMS Outline: In this application our goal is to practices on data validation so we will develop a system to store our orders data and apply the validation on it, I will use aliexpress orders information to build the csv file. As far as i know, aliexpress site is not providing any tool to export a file that contain your orders detail so we will do this just to keep a history records of our orders.

File Structuer: The file will have 8 columns here is a short description of each column:
order_no: A serial number that will increment automatically, we will consider this to be a primary key of the table.
order_id: This is the order id generated by aliexpress site, we will enter it as it is.
order_date: To hold the orders date, the date will be in DD-MM-YYYY format.
order_detail: Short description of the order, even you write it in your words or copy paste it from your order page.
item_price: The price in US$
ship_price: Shipment amount in US$
quantity: The Quantity of the items.
item_url: The URL of the item page.

Coming Post We will start from next post to write the main menu, and the first function to create a csv file and insert the first row.




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Python: Pandas Lesson 12

August 18, 2019 1 comment


Learning : Pandas Lesson 12
Subject: Zoo Management System – P6

In this last post of Zoo Managment System series we will cover two of most important functions after the Adding Records, they are Editing a Record and Deleting Record, both will be in there simplest form with no validations code or try … Exception block.

Editing Record: To edit a record we need to identify it first, so we will use the id then the function will ask the user for each column if he want to change/update the data, if the user select Yes (y) then he will get the prompt to enter the new data, and if he select No (n) then the application will ask him about the other column. Here is the code ..

Edit a Record

def edit_record(df):

clear() # To clear the terminal.

print(‘\n We are in a editing mode, for each column if you want to edit select ”y” if not select ”n”\n’)

# First we will fitch the columns from the df

col_list = []

for each in df.columns :

col_list.append(each)

print(df.to_string(index=False))

print(‘\n Select the id of the rescord you want to edit:’)

edit_id = input(‘ Enter the id : (c for cancel ) ‘)

if edit_id in [‘c’,’C’] :

input(‘ You select to cancel the editing… \n ** Press any key to continue .. . . ‘)

return

else:

for each in col_list:

if each !=’id’:

chose_edit= input(‘\n Do you want to change {} (y or n)’.format(each))

if chose_edit in [‘y’,’Y’]:

you_change = input(‘ Enter the new value: ‘)

df.loc[df[‘id’] == int(edit_id), [each]] = you_change

else:

input(‘\n You select not to change {} press Enter to change another column.’.format(each))

print(‘\n You finish Editing. .. \n ‘)

input(‘\n\n\n\n ** Press any key to continue .. . . ‘)


Here is a screen shot of the code …

Deleting a Record:A last function we will work on is deleting a record. To do this first we will show the user all the rows in the DataFrame then he will select the id of the column to be deleted. Here is the code..

Delete a Record

def delete_record(df1):

clear()

print(‘\n’,df1.to_string(index=False))

del_record = input(‘\n Enter the ”ID” for the record you want to delete: ‘)

#Delete the row with id = del_record 

df1 = df1[df1.id != int(del_record)]

print(‘\n Record been deleted … .. \n ‘)

global df # Reset the df as global variable

df = df1

input(‘\n\n\n\n ** Press any key to continue .. . . ‘)


Now we just finish a simple application to manage our zoo file. When we start writing pandas lessons I select a simple data frame csv file fond on the web, and we work on it as simple as we can to go through a most important functions in any application we plan to write. We did’t cover any validations part or any mistakes the user may do. So to avoid all this I am planning to start working on another project that we will cover any missing part here.

Also I am working on publishing the source code of this application on my download page here..




:: Pandas Lessons Post ::

Lesson 1 Lesson 2 Lesson 3 Lesson 4
Lesson 5 Lesson 6 Lesson 7 Lesson 8
Lesson 9 Lesson 10 Lesson 11 Lesson 12



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