Begin with Python

PYTHONBEGIN WITH

COURSE OUTLINE

Installing and Using Python

Basic I/O

Variables and Expressions

Conditional Code

Functions

Loops and Iteration

Python Data Structures

Errors and Exceptions

Object Oriented with Python

Multithreaded Programming with Python

Install/Create and Using Python Library

Compile Python Script

Resources

INSTALLATION PYTHON INTERPRETER

▸ Download : https://www.python.org/downloads/ (Python 3.5.2)

▸ Install

PREPARATION

https://www.python.org/downloads/


▸ For Windows : https://docs.python.org/3/using/windows.html

PREPARATION

https://docs.python.org/3/using/windows.html


▸ Install Location (Widows) :

PREPARATION

C:\User\<name>\Programs\AppData\Local\Programs\Python\Python35-32

▸ Install Location (OSX)/usr/bin/python

INSTALLATION PYTHON IDE

▸ Download and install pip: https://pip.pypa.io/en/stable/installing/

▸ Install Jupyter IDE : http://jupyter.readthedocs.io/en/latest/install.html

PREPARATION

( pip install jupyter )

https://pip.pypa.io/en/stable/installing/

http://jupyter.readthedocs.io/en/latest/install.html

RUN JUPYTER

PREPARATION

Jupyter: http://localhost:8888

>> jupyter-notebook

Goto : localhost:8888

localhost:8888

WHY PYTHON?

WHY PYTHON?

WHY PYTHON?

WHY PYTHON?

Cross Platform

BASIC I/O

BASIC I/O

“ Hello World “

> text = input(“Enter text”)

> x = int(input(“Enter text”))

> print(“hello”)

> print(10)

> print(text)

> print(“{}”.format(x))

> print(“%s”.%(x))

Input

Output

Input()

print()

VARIABLES AND EXPRESSIONS


> pi = pi + 1

> number += 1

> text = text + “haha”

> n = 2 + 2 * 2 - 5

n ?

Dynamics Variable

Expression

> a = 1

> a = “1”

> a = 1.0

> a = f()


Variable types

boolean : True/False

float : 0.1

int : 100

string : “hello”


>> type()


Quiz Time “ Let me introduce myself “

FRIST NAME: LAST NAME: AGE: GENDER: TEL: WEIGHT (KG.): HEIGHT (CM.) :

MY NAME IS ________________. I AM _________ YEARS OLD. I AM A _________. MY PHONE NO. IS ______________. MY WEIGHT IS ________________KG. (~_________ LB.) MY HEIGHT IS ________________CM. (~__________M.)

Input:

Output:

10 Min. Q1

*1 kg = 2.205 lb

CONDITIONAL CODE

CONDITIONAL CODE

Syntax

if <condition> :

statment(s)

elif <condition> :

statment(s)

else :

statment(s)

Comparators

> , < , >= , <=, not, !=

Operators

A & B , A and B

A | B , A or B

Syntax

short if

x = <true> if <condition> else <false>

CONDITIONAL CODE

Example

if (5 > 10) | (10 > 15) & ( 1 != 1) :

print(False)

elif (10 > 5) & (not(False)):

print(True)

else:

print(NULL)

Example (short if)

x = 5 if 5 > 10 else 10

CONDITIONAL CODE

Quiz Time “ What is my BMI level ?“


MY NAME IS ________________. I AM _________ YEARS OLD. I AM A _________. MY PHONE NO. IS ______________. MY WEIGHT IS ________________KG. (~_________ LB.) MY HEIGHT IS ________________CM. (~__________M.) MY BMI IS : __________________.

Input:

Output:

5 Min. Q2

*1 kg ~ 2.205 lb

LOOPS AND ITERATION

LOOPS AND ITERATION

range#generate number

range(5) ==> [0,1,2,3,4]range(0,10,2) ==> [0,2,4,6,8]range(0,10,5) ==> [0,5]

LOOPS AND ITERATION

enumerate

#generate index i start from 0

for i, n in enumerate(<iterator object>): statement(s)

Example

for i, n in enumerate(range(0,10,5)): pow = n ** i

print(pow)

15

LOOPS AND ITERATION

Syntax

for…

for n in <iterator object>: statement(s)

while..

while(<conditions>): statement(s)

Examples

for…

for n in range(10): print(n ** n)

while..

while(True): break

for n in <iterator object>:

for n in <iterator object>: …….

LOOPS AND ITERATION

break

#exit loop

for n in <iterator object>: break

continue

#next loop

for n in <iterator object>: continue

pass

#pass

while True pass

LOOPS AND ITERATION

Syntax

for…

for n in <iterator object>: statement(s)

while..

while(<conditions>): statement(s)

range#generate index number

range(5) ==> [0,1,2,3,4]range(0,10,2) ==> [0,2,4,6,8]

enumerate

#generate index i start from 0

for i, n in enumerate(<iterator object>): statement(s)

break

#exit loop

for n in <iterator object>: break

continue

#next loop

for n in <iterator object>: continue

FUNCTION

FUNCTIONS

Syntax

def <function name>(args) :

statement(s)


statement(s)

return <value>


statement(s)

yield <value>

return

return 0return 1

g = make_generator()

print(g)0

FUNCTIONS

Argument

def <function name>(x, y) : statement(s)

Argument : Default value

def foo(x = 1, y = 2) : statement(s)

Call function and parse values

fn(3,2) #args

fn(x = 2, y = 1) #kwargs

Argument : *args, **kwargs

def fn(x = 1, y = 2, *args)def fn(x = 1, y = 1, **kwargs)def fn(x = 1, y = 1,*args, **kwargs)

FUNCTIONS

Return

def <function name>(x, y) :

statement(s)

return value

Return

def <function name>(x, y) :

statement(s)

return value1, value2,…

Return values

x , y = minmax(x,y)

Example

def add(x, y) :

a = x + y

return a

Example

def minmax(x, y) : if x == y: return None, None

mi = x if x < y else y ma = x if x > y else y

return mi, ma

FUNCTIONS

Example

def BMI(weight=None, height =None):

bmi = weight / (height ** 2)

return bmi

bmi = BMI(10,1.67)

FUNCTIONS

#Variable scope

r = 1for a in range(10): r = 3 for i in range(5): r = 8

print(r) ????

#Variable scope

a = 5def var(): print(a)

var() ????

#Variable scope

a = 5def var(): a += 5 print(a)

var() ????

FUNCTIONS

#Variable scope

a = 5def var(): global a a += 5 print(a)

var() ????

“UnboundLocalError: local variable 'a' referenced before assignment“

FUNCTIONS

Quiz Time10 Min. Q3

“ What is my BMI level? : Function Version“

F1 : getInfo() #get user information and return informations

F2 : BMI(…. , ……) #calculate and return BMI level

F3 : showInfo(…,….,…,..) #display summary information

# get information, calculate BMI and display of N users

F4 : getNInfo(n)

FUNCTIONS

#main program

import bmi

bmi.getInfo()bmi.BMI(weight,height)bmi.showInfo()

#External function#bmi.py

def getInfo():………def BMI(weight,height):……..def showInfo(….,..,.…):………

#main program

from bmi import bmi

bmi.getInfo()bmi.BMI(weight,height)bmi.showInfo()

# External module function# bmi/bmi.py

def getInfo():………def BMI(weight,height):……..def showInfo(….,..,.…):………

PYTHON DATA STRUCTURES



- LIST

- TUPLE

- SET

- DICT

- FILE


List [1,2,3,4,5,6,7,8,9,10]

_list = [1, ”A”, [1], 1.0] #multiple type in one list object

a = _list[0] #access one element

b = _list[0:3] #access multiple elements

_list.append(10) #add new element

_list.pop(), _list.pop(index) #remove using index

_list.remove(value) #remove using value


Using Lists as Stacks stack = [3, 4, 5]stack.append(6)stack.append(7)print(stack)stack.pop()print(stack)stack.pop()stack.pop()print(stack)


Using Lists as Queues from collections import deque

queue = deque(["Eric", "John", "Michael"]) queue.append("Terry") queue.append("Graham") queue.popleft() queue.popleft() print(queue)


Add element squares = []

for x in range(10): squares.append(x**2)

print(squares)


Generate list squares = [x**2 for x in range(10)]

squares = list(map(lambda x: x**2, range(10)))

map map( lambda <> , <>, <input>) #~ short for


Nested List matrix = [

[1, 2, 3, 4],

[5, 6, 7, 8],

[9, 10, 11, 12],

]


Access Nested List for i in matrix:

for j in i:

print(j)

123456789101112


Transpose List list(zip(*matrix))

[(1, 5, 9), (2, 6, 10), (3, 7, 11), (4, 8, 12)]

len() #find size of list len([1,2,3,4,5,6,7,8,9])

9


sum(), min(), max() a = [1,2,3,4,5,6,7,8,9,10]print(sum(a), min(a), max(a))

55 1 10

sorted a = [10,2,3,4,5,6,7,8,9,1]print(sorted(a))

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]


Concat List a = [1,2,3,4]b = [5,6,7,8,9]c = a + b

print(c)

[1,2,3,4,5,6,7,8,9]


del #remove list or elements list a = [-1, 1, 66.25, 333, 333, 1234.5]

del a[0] del a[2:4]del a[:] del a #remove variable “a” from memory

FUNCTIONS

Quiz Time10 Min. Q4

“ STATISTICS Time“

1. Loop for get 10 numbers from input and insert to list

2. Create function for calculate: - Mean (Average) - Min- Max- Variance #calculate from the equation only

3. Show values

http://www.mathsisfun.com/data/standard-deviation.html

http://www.mathsisfun.com/data/standard-deviation.html


Tuple #sequence data (1,2,3,4,5,6,7,8,9,10)

_tuple = 4,5,6,[1],"hello" #multiple type in one Tuple object

a = _tuple[0] #access one element

b = _tuple[0:3] #access multiple elements

_tuple.count(x) #count number of x in tuple

_tuple.index(x) #find index of x in tuple

_tuple[0] = 1 #cannot edit element value in tuple


Concat Tuple a = 1,2,3,4,5,6,[1],”hello"

a += tuple([100])

print(a)

(1, 2, 3, 4, 5, 6, [1], 'hello', 100)


List to Tuple t = tuple([1,2,3,4,5,6])

print(t)

(1, 2, 3, 4, 5, 6)

print format using tuple print(“%s > %s ” %(50,10) )

50 > 10


Sets {'apple', 'orange', 'apple', 'pear', 'orange', 'banana'}

_set = {'apple', 'orange', 'apple', 'pear', 'orange', 'banana'} #multiple type in one set object

a = _set.pop() #get first element of set

_set.remove(x) #remove element x

_set.add(x) #add new element

len(_set) #get size of set


_set.intersection(a) #get intersect element on set a

_set.issubset(a) #Is subset of set a?

_set.difference(a) #get difference element from set a

_set.union(a) #get union element with set a


Sets a = {'apple', 'orange', 'apple', 'pear', 'orange', ‘banana'} print(a)

{'apple', 'orange', 'banana', 'pear'}

a = set(“ABCDEFG”)print(a)

{'E', 'B', 'A', 'F', 'G', 'C', 'D'}


a = set([4,5,1,2,3])print(a)

{1, 2, 3, 4, 5} #element will be sorted automatically

a = set([4,5,1,2,3])b = set([4,5,1])print(a.intersection(b))

{1, 4, 5}


Quiz Time5 Min. Q5

“ Like Number “

Similarity?


Quiz Time5 Min. Q5

“ Like Number “

{11, 2, 3, 4, 15, 6, 7, 8, 9, 10} {15, 2, 3, 4, 15, 6, 17, 8, 19, 10}

Choose 10 numbers between 0 - 20


Quiz Time5 Min. Q5

“ Like Number “


Quiz Time5 Min. Q5

“ Similar Like Number “

IR = {11, 2, 3, 4, 15, 6, 7, 8, 9, 10}

CA = {15, 2, 3, 4, 15, 6, 17, 8, 19, 10}

SIM (IR,CA) = 0.58333


Quiz Time5 Min. Q5

“ Like Number “

1. Get two set of numbers(10 numbers) from two users.

2. Create function for calculate Jaccard similarity

3. Display the similarity.


Dict {'apple' : 0, 'orange' : 1, 'pear' : ‘Hello'} #key, value structure

_dict = {'apple' : 0, 'orange' : 1, 'pear' : ‘Hello'} #multiple type in one dict object

_dict.pop() #get first element of dict

_dict.keys() #get all key of dict

_dict.values() #get all value of dict

_dict[index] = x #add new element to dict (key,value)

len(_dict) #get size of dict


a = {'apple' : 0, 'orange' : 1, 'pear' : ‘Hello'} print(a[‘apple’])

0

a = {'apple' : 0, 'orange' : 1, 'pear' : ‘Hello'} for k in a: print(a[k])

01‘hello’


a = {'apple' : 0, 'orange' : 1, 'pear' : ‘Hello'} print(a.values())

dict_values([0, 1, 'Hello'])

a = {'apple' : 0, 'orange' : 1, 'pear' : ‘Hello'} print(a.keys())

dict_keys(['apple', 'orange', 'pear'])


File

f = open(<filename>,’r’) #open file for read

f = open(<filename>,’w’) #open file for write new

f = open(<filename>,’a’) #open file for write append

f.readline() #read next line

f.readlines() #read all lines

f.close() #read all lines


file.txtMy name is python.I am a programmer.I have no life.

with open(“file.txt” , ’r’) as f: first = f.readline() for line in f: print(line)

My name is Python.

I am a programmer.

I have no life.



with open(“file.txt” , ’r’) as f: lines = f.readlines() print(lines)

['My name is Python.\n', 'I am a programmer.\n', 'I have no life.']


with open(“write.txt” , ’w’) as f: f.write(“Hello\n”)

write.txt

Hello

with open(“write.txt” , ’a’) as f: f.write(“World\n”)

write.txtHelloWorld



f = open(“file.txt” , “r”)lines = f.readlines()print(lines)f.close()

['My name is Python.\n', 'I am a programmer.\n', 'I have no life.']


String str = “hello world” #create string

len(str) #get string length

str[i:j] # get string from index i to index j - 1

str[i] #get character at index i

str.replace(str1,str2) #replace str1 with str2 in string str

https://docs.python.org/2/library/string.html

str.splite(sep) #split string by string sep

https://docs.python.org/2/library/string.html


str = “Hello world”

print(len(str))

11


print(str[0:3])

Hel



print(str.replace(“o”,”_”))

Hell_ w_rld


print(str.split(“ ”))

['Hello', 'world']


Quiz Time10 Min. Q6

“ Word Count “

file.txtMy name is pythonI am a programmerI have no life

I : 2my : 1name : 1is : 1……..

1. Use dictionary structure to store words and count number each word in the document.

2. Show output , by using print command to show values indictionary Ex. print(dict).

ERROR AND EXCEPTION

ERROR AND EXCEPTION

ERROR AND EXCEPTION

try:

...

except SomeException:

e = sys.exc_info()[1]

print(e)

https://docs.python.org/3/library/exceptions.html


ERROR AND EXCEPTION

import sys

try:

str = "hello"

print(str[100])

except:

tb = sys.exc_info()[1]

print(tb)


string index out of range


ERROR AND EXCEPTION

Input validation

while(True):

try:

n = int(input("age : "))

break

except:

print("Age is invalid, please try agian.")




Quiz Time “ Input validation “


5 Min. Q7

Create function for validate input value

OBJECT ORIENTED WITH PYTHON



class ClassName:

'Optional class documentation string'

class_suite

https://www.tutorialspoint.com/python/python_classes_objects.htm

1. The class has a documentation string, which can be accessed via ClassName.__doc__.

2. The class_suite consists of all the component statements defining class members, data attributes and functions




class Employee:

'Common base class for all employees'

empCount = 0

def __init__(self, name, salary):

self.name = name

self.salary = salary

Employee.empCount += 1

def displayCount(self):

print("Total Employee %d") % Employee.empCount




Creating Instance Objects

emp1 = Employee("Zara", 2000)emp2 = Employee("Manni", 5000)

Accessing Attributes

emp1.displayEmployee()

emp2.displayEmployee()

print "Total Employee %d" % Employee.empCount




Class Inheritanceclass SubClassName (ParentClass1[, ParentClass2, ...]):

'Optional class documentation string'

class_suite




class Parent:

parentAttr = 100

def __init__(self): print(“Calling parent constructor”)

def parentMethod(self): print(‘Calling parent method’)

def setAttr(self, attr): Parent.parentAttr = attr

def getAttr(self): print(“Parent attribute :", Parent.parentAttr)

class Child(Parent):

def __init__(self):

print(“Calling child constructor”)

def childMethod(self):

print(‘Calling child method’)

Accessing

c = Child() # instance of childc.childMethod() c.parentMethod() c.setAttr(200) c.getAttr()




Overriding Methods

class Parent: def myMethod(self): print 'Calling parent method'

class Child(Parent): def myMethod(self): print 'Calling child method'

c = Child() # instance of child

c.myMethod() # child calls overridden method




Data Hiding

class JustCounter: __secretCount = 0 #add double underscore prefix

def count(self): self.__secretCount += 1 print self.__secretCount

counter = JustCounter()counter.count()counter.count()print counter.__secretCount

AttributeError: JustCounter instance has no attribute '__secretCount'



Quiz Time10 Min. Q8

“ My Car“

Create class of a car

MULTITHREADED PROGRAMMING




Background Executor

thread.start_new_thread ( function, args[, kwargs] )

import threadimport time

# Define a function for the threaddef print_time( threadName, delay): count = 0 while count < 5: time.sleep(delay) count += 1 print "%s: %s" % ( threadName, time.ctime(time.time()) )

# Create two threads as followstry: thread.start_new_thread( print_time, ("Thread-1", 2, ) ) thread.start_new_thread( print_time, ("Thread-2", 4, ) ) except: print "Error: unable to start thread"

while 1: pass


Parallele Processing

p = Pool(<Number of Executor>)p.map(<function>,data)

from multiprocessing import Pool

def f(x): return x*xp = Pool(5)ans = p.map(f, [1, 2, 3])

[1, 4, 9]

- Use it if you have more than one/two cores on your computer and more data point, overhead will occur when start new thread

INSTALL/CREATE AND USING PYTHON LIBRARY



“ pip install <packet name> ”install via pip

Ex. pip install pickle

pickle.dump()pickle.load()


“ python setup.py install ”

install via source code

https://github.com/tomerfiliba/rpyc

https://github.com/tomerfiliba/rpyc


Using libraryimport <packet name>from <packet folder name> import <packet name>

import timet = time.time()

from date time import datetimedt = datetime.now()


Where is library install pathimport syssys.path

import timet = time.time()

from date time import datetimedt = datetime.now()


Remote Python Callpip install rpyc or download add install via “python setup.py install”

def printMe(text) printMe(text)


import rpyc from rpyc.utils.server import ThreadedServer

class MyService(rpyc.Service): def exposed_add(self, a, b): return a + b

def exposed_sub(self, a, b): return a - b

def exposed_mul(self, a, b): return a * b

def exposed_div(self, a, b): return a / b

def foo(self): print “foo"

if __name__ == "__main__": server = ThreadedServer(MyService, port = 12345)

server.start()

client slide

import rpyc

import rpyc

conn = rpyc.connect("localhost", 12345) x = conn.root.add(4,7)print(x)

server slide

COMPILE PYTHON SCRIPT



1. Goto source code directory

2. “ python -m compile all . “

Save time when load to execute again.

Software

Begin with Python