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the python training helps people learn python - part4
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release_python_day4_slides_201606_1.pdf
- 2. Agenda of Python Programming Day 1 - Basic Python Day 2 - Advanced Python Day 3 - Web Scraping with Python Day 4 - Web application with python
- 6. Courses agenda – Day4 1. Working with CRUD, Database and ORM 2. Making http server 3. Developing Web with framework – flask 4. Access GPIOs in Raspberry PI 5. Control LCD in Raspberry PI 6. Project – using Flask and python access to I/O to make a simple control center of Raspberry pi via web
- 18. Creating database and ORM RAW SQL – create 2 tables – restaurant/menu_item Python has no way in helping me if typo
- 20. SQLAlchemy
- 24. SQLAlchemy - Creating a Database A mapper code create the variables as we create Each column of the table in the database when we create a column we need to pass in some attribute in it
- 28. ORM CRUD – Create Refer to CRUD.ipynb
- 30. Exercise - 1 • Implement a db_setup.py by using configure/class/table/mapper we told previously 1. Setup a new database called employee.db 2. Create 2 tables – one named Employee and another names Address by ORM 3. Create the column with the proper datatype and its foreign key relationship 4. Open employee.db by DB Browser for SQLite http://sqlitebrowser.org/ to check if you created correctly
- 31. ORM CRUD – READ Refer to CRUD.ipynb
- 33. ORM CRUD – READ
- 35. • Count() • Filter() – 基本就是select query的幾個常用function
- 37. Exercise-2 • Retrieve what “Urban Burger” and ‘Super Stir Fry‘ offer – print their menu name and price • Run addmoremenus_second_version.py to populate more menu item
- 38. Exercise-2 • Retrieve the offer of non-English restaurant • Retrieve the restaurants offering ‘French Fries’with price smaller than $3 and each dish’s description and price
- 42. ORM CRUD – UPDATE By using DB browser for SQLite
- 43. ORM CRUD – DELETE Auntie Ann‘s Diner wants to remove Spinach Ice Cream from its menu
- 44. CRUD: DELETE
- 45. QUIZ delete
- 47. HTTP server
- 48. HTTP server
- 49. HTTP server
- 50. HTTP server
- 54. Exercise-3 Deal with Multiple GET request • Add two URLs • /nihao (你好) • /konnichiwa (こんにちは) • Read two html files for each requests • html_jp.html ; html_tw.html • Test by your browsers or the codes below
- 57. Introducing Frameworks and Flask Frameworks is the collection of codes that allows you to focus on your tasks There’re hundred of frameworks
- 61. The first Flask
- 69. Routing Dynamic routing • Print all menu items based on restaurant id from url flask_server_3.py
- 70. Templates • Creating html by the way below isn’t fun • Flask has its template engine to let you create your micro template for your html snippet Hard coding not good Syntax
- 75. Templates
- 76. URL building It helps to build URL string with arguments to link to other pages
- 79. Request form Making the form by POST to create a new restaurant and return the result page c c c
- 81. Styling
- 89. Raspberry Pi
- 90. Raspberry Pi
- 92. GPIO • Can be configured to be input (read HIGH/LOW – 3.3v or 0 v) or output • a 40-pin header marked J8, arranged as 2x20 pins All the GPIO pins can be reconfigured to provide alternate functions, UART, SPI, PWM, I²C and so providing a total of 17 GPIO pins http://elinux.org/RPi_Low-level_peripherals https://pinout.xyz/pinout/pin22_gpio25
- 94. GPIO
- 96. GPIO RPi.GPIO a small py library that take some of the complexity out of driving the GPIO pins #1.Import GPIO module import RPi.GPIO as GPIO #2.Pin numbering GPIO.setmode(GPIO.BOARD) # or GPIO.setmode(GPIO.BCM) mode = GPIO.getmode() #3.Setup up a channel GPIO.setup(channel, GPIO.IN or GPIO.OUT) # Multiple channel chan_list = [11,12] GPIO.setup(chan_list, GPIO.OUT) #INPUT or OUTPUT # END - cleanup GPIO.cleanup() $ wget http://pypi.python.org/packages/source/R/RPi.GPIO/RPi.GPIO-0.6.0.tar.gz $ tar zxf RPi.GPIO-0.6.0.tar.gz $ cd RPi.GPIO-0.6.0 $ sudo python setup.py install
- 100. Python Concurrency Concurrency : 1) Doing more than one thing at a time. Example : 1) A network server that communicates with several hundred clients all connected at once 2) A big number crunching job that spreads its work across multiple CPUs
- 103. Python Concurrency Shared Memory Processes Separate process Fork, Pipes, FIFOs, memory mapped regions, etc
- 104. Python Concurrency Threads • An independent task running inside a program • Shares resources with the main program (memory, files, network connections, etc.) • Has its own independent flow of execution(stack, current instruction, etc.)
- 105. Python Concurrency
- 106. Python Concurrency import time import threading class CountdownThread(threading.Thread): def __init__(self,count): threading.Thread.__init__(self) self.count = count def run(self): while self.count > 0: Print("Counting down", self.count) self.count -= 1 time.sleep(5) return inherit from Thread and redefine run() This code executes in the thread First way: threads are defined by a class
- 107. Python Concurrency t1 = CountdownThread(10) # Create the thread object t1.start() # Launch the thread t2 = CountdownThread(20) # Create another thread t2.start() # Launch First way: threads are defined by a class
- 108. Python Concurrency def countdown(count): while count > 0: print "Counting down", count count -= 1 time.sleep(5) t1 = threading.Thread(target=countdown,args=(10,)) t1.start() Second way: threads are defined by a class
- 110. GPIO output
- 113. Exercise-7 • Give a try to the previous code • Add Adjust_brightness(value) to the LED class • Pass in 0 ~ 10 to control the brightness of LED by using ChangeDutyCycle() • Add blinking() to brighten/dim your LED by ChangeDutyCycle()
- 115. GPIO input GPIO.setup(channel, GPIO.IN, pull_up_down=GPIO.PUD_UP) # or GPIO.setup(channel, GPIO.IN, pull_up_down=GPIO.PUD_DOWN) The RPi.GPIO module allows you to configure the Broadcom SOC to do this internally in software
- 116. GPIO input
- 121. GPIO input
- 124. Qc1602a LCD
- 127. LCD模組通常會提供兩種模式:4-bit 和 8-bit。 8-bit模式會使用8支接腳來傳輸在資料或指令，可以一個動作送出/讀 入完整的 8 個 bit(1 byte) 數據。 4-bit模式則只需要使用4支接腳來傳輸在資料或指令，但是一個動作 只能送出/讀入4個bit的數據，所以要送出/讀入完整的一個 byte 要多 花一個Cycle。 http://blog.ittraining.com.tw/2014/12/raspberry-pi-b-python-lcd-16x2-hd44780.html Connection between LCD/RPI
- 128. http://blog.ittraining.com.tw/2014/12/raspberry-pi-b-python-lcd-16x2-hd44780.html 透過這些GPIO pin腳來對LCD下達命令 or寫入一個個的8bit(1 byte)資 料. 假設想要移動游標的位置到第一行第一格的位置 使用 set DDRAM address的命令 0x80 (轉換成二進位 0b 1000 0000 ) Connection between LCD/RPI
- 131. Write lower 4 bit http://blog.ittraining.com.tw/2014/12/raspberry-pi-b-python-lcd-16x2-hd44780.html
- 133. Write Data http://blog.ittraining.com.tw/2014/12/raspberry-pi-b-python-lcd-16x2-hd44780.html • 指令"0x80"寫入之後，就會把游標移動到顯示螢幕 上第一行第一格的位置。 • 此時要在這個位置顯示ASCII字元"A",ASCII表中的16 進位值為0x41二進位為0b0100 0001)，哪要怎麼寫入 "資料"?
- 141. 1. 在LCM模組上第一行和第二行顯示Hello Python Hint:運用 LCD setup codes – check LCD.ipynb 2. 在LCM模組上第一行奇數位址和第二行奇數位址 顯示”Hello” hint: use 0x80 + col-1 and 0xc0 + col-1 to get the pos in first and second line Exercise -9
- 142. Exercise -9 3. 實作 move_cursor(line, col) hint: use this express: (line-1) * 0x40 + 0x80 + (col-1) to get the position print_line_1(msg) #參數為字串 在LCD第一行印出 print_line_2(msg) #參數為字串 在LCD第二行印出 clear_line_1 & 2程式 #將LCD第一二行清空 (just fill in “ “)
- 143. 4. 配合subprocess.check_output() 呼叫指令ifconfig 得到IP 位置，並將其 顯示在LCM模組之上。(hint: use decode().split() to separate each line and look for "addr:“) 5. 將以上所用function改寫成class, 並讓開機時候將 hostname 與 ip顯示在 lcd上(hint: $sudo nano /etc/rc.local and add python script before exit() ) Exercise - 9
- 146. Environment Setup DHCP (IP) assignment SSH/VNC Flask Web Server PORT:80 File Share Samba PAULRPI PAULYANG IPHONE IP: 172.20.10.2 ~ 14 IP: 172.20.10.1
- 147. DIR structure
- 150. Requirement 3. Create get_soc_temp.py to get temp by using subprocess and check_output function temp = subprocess.check_output("/opt/vc/bin/vcgencmd measure_temp", shell=True) And write into sqlite database
- 154. Reference Raspberry Pi online resource 1) https://www.raspberrypi.org/documentation/hardware/raspberrypi/schematics/Raspberry-Pi-B- Plus-V1.2-Schematics.pdf 2) http://www.geeetech.com/wiki/index.php/Raspberry_Pi_Model_B%2B 3) http://blog.ittraining.com.tw 4) https://www.pubnub.com/blog/2015-08-04-building-raspberry-pi-smart-house-part-2 5) http://elinux.org/RPi_Low-level_peripherals 6) http://www.thirdeyevis.com/pi-page-2.php 7) https://www.pubnub.com/blog/2015-08-04-building-raspberry-pi-smart-house-part-2/ 8) https://sourceforge.net/p/raspberry-gpio-python/wiki/PWM/ 9) https://www.adafruit.com/datasheets/TC1602A-01T.pdf Udacity - Full-Stack-Foundations 1) www.udacity.com Concurrency 1) http://www.dabeaz.com/usenix2009/concurrent/ 2) https://pymotw.com/2/threading/
- 155. BACKUP