Archive
Python and Lindenmayer System – P3
Learning : Lindenmayer System P3
Subject: Drawing Fractal Tree using Python L-System
In the first two parts of the L-System posts (Read Here: P1, P2) we talk and draw some geometric shapes and patterns. Here in this part 3 we will cover only the Fractal Tree and looking for other functions that we may write to add leaves and flowers on the tree.
Assuming that we have the Pattern generating function and l-system drawing function from part one, I will write the rules and attributes to draw the tree and see what we may get.
So, first tree will have:
# L-System Rule to draw ‘Fractal Tree’
# Rule: F: F[+F]F[-F]F
# Angle: 25
# Start With: F
# Iteration : 4
and the output will be this:
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If we need to add some flowers on the tree, then we need to do two things, first one is to write a function to draw a flower, then we need to add a variable to our rule that will generate a flower position in the pattern. First let’s write a flower function. We will assume that we may want just to draw a small circles on the tree, or we may want to draw a full open flower, a simple flower will consist of 4 Petals and a Stamen, so our flower drawing function will draw 4 circles to present the Petals and one middle circle as the Stamen. We will give the function a variable to determine if we want to draw a full flower or just a circle, also the size and color of the flowers.
Here is the code ..
font = 516E92
commint = #8C8C8C
Header here
# Functin to draw Flower
def d_flower () :
if random.randint (1,1) == 1 :
# if full_flower = ‘y’ the function will draw a full flower,
# if full_flower = ‘n’ the function will draw only a circle
full_flower = ‘y’
t.penup()
x1 = t.xcor()
y1 = t.ycor()
f_size = 2
offset = 3
deg = 90
if full_flower == ‘y’ :
t.color(‘#FAB0F4’)
t.fillcolor(‘#FAB0F4’)
t.goto(x1,y1)
t.setheading(15)
for x in range (0,4) : # To draw a 4-Petals
t.pendown()
t.begin_fill()
t.circle(f_size)
t.end_fill()
t.penup()
t.right(deg)
t.forward(offset)
t.setheading(15)
t.goto(x1,y1 – offset * 2 + 2)
t.pendown() # To draw a white Stamen
t.color(‘#FFFFF’)
t.fillcolor(‘#FFFFFF’)
t.begin_fill()
t.circle(f_size)
t.end_fill()
t.penup()
else: # To draw a circle as close flower
t.pendown()
t.color(‘#FB392C’)
t.end_fill()
t.circle(f_size)
t.end_fill()
t.penup()
t.color(‘black’)
Then we need to add some code to our rule and we will use variable ‘o’ to draw the flowers, also I will add a random number selecting to generate the flowers density. Here is the code for it ..
In the code the random function will pick a number between (1-5) if it is a 3 then the flower will be drawn. More density make it (1-2), less density (1-20)
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And here is the output if we run the l-System using this rule: Rule: F: F[+F]F[-F]Fo
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Using the concepts, here is some samples with another Fractal Tree and flowers.
Another Fractal Tree without any Flowers.
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Fractal Tree with closed Pink Flowers.
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Fractal Tree with closed Red Flowers.
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Fractal Tree with open pink Flowers.
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To Download my Python code (.py) files Click-Here
Follow me on Twitter..Python and Lindenmayer System – P2
Learning : Lindenmayer System P2
Subject: Drawing with python using L-System
In the first part of Lindenmayer System L-System post (Click to Read) we had wrote two functions: one to generate the pattern based on the variables and roles, and one to draw lines and rotate based on the pattern we have.
In this part I will post images of what Art we can generate from L-System
the codes will be the L-system that generate the patterns, so the code will include: the Rules, Angle (Right, Left) Iteration and Starting Variable.
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L-System: Koch Curve  |
L-System: Minkowski Sausage |
L-System: … but here the Iteration is: 3  |
L-System: Again … but here the Iteration is: 3  |
L-System: Square Sierpinski  |
L-System: Sierpinski Arrowhead.  |
L-system: Dragon Curve |
L-System: Koch Snowflake  |
L-System:  |
L-System:  |
The possibilities to generate the putters and therefore drawing the output is endless, any slightly changes in the iterations or rotation (+ -) angles will take all output to a new levels. In the coming post, I will use the L-system to generate fractal tree and see what we can get from there.
To Download my Python code (.py) files Click-Here
Python and Lindenmayer System – P1
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
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# 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 |
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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.
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To Download my Python code (.py) files Click-Here
Python: Date Validation Function
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
Python: Drawing Shapes
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()
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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 ..
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Now if we call the function number of times equal to it’s heads what we will get ? let’s see . .. Click to enlarge ..
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And take a look when we set the numbers to 20. .. Click to enlarge ..
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To Download my Python code (.py) files Click-Here
Python: Random Squares
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.
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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.
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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.
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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
Python Project: Ant Escaping Path
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
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To Download my Python code (.py) files Click-Here
Python: Orders Manager P4
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()
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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 .. . . ‘)
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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.
Python: Orders Manager P3
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’
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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.
Python: Orders Manager P2
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..
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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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