python code camp for professionals 3/4
TRANSCRIPT
Build a Better Python Web APP
MongoDB• Much faster than SQL databases
• No need to learn query languages* and setups
• Easier to scale when designed properly
Install pymongopip install pymongo
easy_install pymongo
Hello Worldfrom pymongo import MongoClient
client = MongoClient("localhost", 27017)db = client.databasename
Stepfrom pymongo import MongoClientImport MongoClient from pymongo
client = MongoClient("localhost", 27017)Connect to the mongodb server at the IP address and port defined
db = client.databasenameAccess a specific database in the mongodb server
collection = db.collectionnameAccess a specific collection (table in SQL) in the selected db
Basic DB Operations
•Create
•Read
•Update
•Delete
Create@route("/user/list")def listuser():
usercursor = db.users.find({},{"_id":False})users = list(usercursor)return {"users":users}
Stepusercursor = db.users.find({},{"_id":False})Find all entries in the collection named users and do not show the _id field
users = list(usercursor)Convert the cursor object into a list, which we can be converted to a json object
return {"users":users}Return the list of users to the browser
The Query Formatdb.collectionname.find(filter,projection) Filter is the expression that needs to be true an element to be includedExamples:• {} = will return all• {“name”:”paolo”} = will only return entries with name
exactly to “paolo”• {“name”:”paolo”, “age”:{“$lte”:30}} = will only return
entries with names exactly “paolo” and age is less than or equal to 30
See more filter operators here: https://docs.mongodb.com/manual/reference/operator/query/
ReadVia query string@route('/sum')def sum(): total = 0 start = request.query.get("start") end = request.query.get("end") for i in range(start,end): total += i return "Sum of "+str(start) + " to " + str(end) + " = " + str(total)
Visit: localhost:8001/sum?start=1&end=10
Inputs in BottleVia POST body@route('/login', method="POST")def login(): username = request.forms.get("username") password = request.forms.get("password") acceptedpasswords = ["gloopgroup", "devconph" , "adventuretime"] if password in acceptedpasswords: return "Welcome "+ username else: return "Unauthorized"
Visit: localhost:8001/login using login page
Activity 1Create a calculator api:http://localhost:8001/operation/operand1/operand2will return the value ofoperand1 <operation> operand2
Example:/subtraction/10/2 will output 8
Common Return TYPESPlain TextSimilar to what we were doing earlier
Common Return TYPESBinaryWhen returning files like images, video, audio, pdfs…
Common Return TYPESJSONThe common return type for APIsExample: FB API/{userid}/friends
{ "data": [ { "name": "Terence Pua", "id": "608407" }, { "name": "Gene Paul Quevedo", "id": "10153785024974240" }, { "name": "Jc Velasquez", "id": "722462218" }, { "name": "Jomel C. Imperio", "id": "779287017" } ], "summary": { "total_count": 770 }}
Common Return TYPESHTMLReturn web pages with dynamic/static content<!DOCTYPE html><html itemscope itemtype="http://schema.org/QAPage"><head>
<title>regex - Validate email address in JavaScript? - Stack Overflow</title> <link rel="shortcut icon" href="//cdn.sstatic.net/Sites/stackoverflow/img/favicon.ico?v=4f32ecc8f43d"> <link rel="apple-touch-icon image_src" href="//cdn.sstatic.net/Sites/stackoverflow/img/apple-touch-icon.png?v=c78bd457575a"> <link rel="search" type="application/opensearchdescription+xml" title="Stack Overflow" href="/opensearch.xml"> <meta name="twitter:card" content="summary"> <meta name="twitter:domain" content="stackoverflow.com"/> <meta property="og:type" content="website" />
<meta property="og:image" itemprop="image primaryImageOfPage" content="http://cdn.sstatic.net/Sites/stackoverflow/img/[email protected]?v=73d79a89bded&a" /> <meta name="twitter:title" property="og:title" itemprop="title name" content="Validate email address in JavaScript?" /> <meta name="twitter:description" property="og:description" itemprop="description" content="How can an email address be validated in JavaScript?" /> <meta property="og:url" content="http://stackoverflow.com/questions/46155/validate-email-address-in-javascript"/> <link rel="canonical" href="http://stackoverflow.com/questions/46155/validate-email-address-in-javascript" />
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script> <script src="//cdn.sstatic.net/Js/stub.en.js?v=d33f759d1183"></script> <link rel="stylesheet" type="text/css" href="//cdn.sstatic.net/Sites/stackoverflow/all.css?v=a13f0e8d2a4f">
<link rel="alternate" type="application/atom+xml" title="Feed for question 'Validate email address in JavaScript?'" href="/feeds/question/46155"> <meta name="twitter:app:country" content="US" /> <meta name="twitter:app:name:iphone" content="Stack Exchange iOS" /> <meta name="twitter:app:id:iphone" content="871299723" /> <meta name="twitter:app:url:iphone" content="se-zaphod://stackoverflow.com/questions/46155/validate-email-address-in-javascript" /> <meta name="twitter:app:name:ipad" content="Stack Exchange iOS" /> <meta name="twitter:app:id:ipad" content="871299723" /> <meta name="twitter:app:url:ipad" content="se-zaphod://stackoverflow.com/questions/46155/validate-email-address-in-javascript" /> <meta name="twitter:app:name:googleplay" content="Stack Exchange Android"> <meta name="twitter:app:url:googleplay" content="http://stackoverflow.com/questions/46155/validate-email-address-in-javascript"> <meta name="twitter:app:id:googleplay" content="com.stackexchange.marvin"> <script>
Returning JSON ObjectJSONSimply return a dictionary or list@route("/json")def jason(): return {"lastname":"bourne", "alias":"David Webb"}
Returning Static HTMLHTMLUse static_file from bottle@route("/loginpage")def loginpage(): return static_file("login.html", root=".")
Testing the POST Handler
Visit localhost:8081/loginpage
Type your name and use any of these as passwordggloopgroup, devconph, adventuretime
Click submit
The POST Request Cycle<form action="/login" method="POST">Method dictates what kind of request happens when submittedAction tells the browser where to submit the request
<input type="text" name="username">Adds a text input that will be associated to the username field
<input type="password" name="password">Adds a password input that will be associated to the password field
<input type="submit">Adds a button that submits the form when clicked
Returning Dynamic HTMLHTMLUse a templating engine:• Library that can substitute variables into a template quickly and cleanly• Isolates the designer’s job of designing and the coder’s job of coding
Install Tenjinpip install tenjin
easy_install tenjin
Using Tenjinfrom gevent import monkey; monkey.patch_all()from bottle import run, route, requestimport tenjinfrom tenjin.helpers import *
@route("/introduction/<name>/<age>/<work>")def template1(name, age, work):
context = {"name":name, "age":age, "work":work}return engine.render("introduction.html", context);
engine = tenjin.Engine(path=['.'])run(server='gevent', host="localhost", port=8001, debug=True)
The template<!doctype html><html lang="en"><head>
<title>Login</title></head><body>
<h1>${name}</h1><h2>Age:${age}<h2><h2>Work:${work}<h2>
</body></html>
Stepfrom gevent import monkey; monkey.patch_all()from bottle import run, route, requestimport tenjinfrom tenjin.helpers import *Import all libraries, including tenjin and all helper methods
@route("/introduction/<name>/<age>/<work>")Define a route for the url, and define variables in it
def template1(name, age, work):Declare a request handler and receive the variables from the url
Stepcontext = {"name":name, "age":age, "work":work}Define a context variable, which is a dictionary of values that will be substituted into the template
return engine.render("introduction.html", context);Render the template called introduction.html using the context variable named context, and return it to the browser
engine = tenjin.Engine(path=['.'])Instructs the templating engine to look for the templates in the directories listed in path
Step (Inside the template)
<!doctype html><html lang="en"><head>
<title>Login</title></head><body>
<h1>${name}</h1><h2>Age:${age}<h2><h2>Work:${work}<h2>
</body></html>
{"name":"Paolo", "age":"30", "work":"Synergist"
}+
Displaying Lists@route("/spell/<word>")def template1(word):
letters = list(word)context = {"letters":letters, "word":word}return engine.render("speller.html", context);
Step@route("/spell/<word>")Define a route that accepts a variable assigned to word
def speller(word):Define a handler that accepts a variable named word
letters = list(word)Convert the text string into a list object. From a string “word”, it becomes a list [“w”, “o”, “r”, “d”]
Stepcontext = {"letters":letters}Define a context variable, which contains the list of letters we just created
return engine.render("speller.html", context);Render the template called speller.html using the context variable named context, and return it to the browser
Step (Inside the template)
<?py for letter in letters: ?>Loop on the elements of the list named letters
<h3>${letter}</h3><br>Display the element letter along with the html
<?py #endfor ?>Denote where the loop ends in the template
<a href="/greet/${word}">greet ${word}</a>Create a link that will call the greet API we created earlier
{"letters":["s", "u", "s", "h", "i"]}
Highlighting Names@route("/profiles/<name>")def profile(name):
users = [{"name":"Em", "image":"http://goo.gl/aDxeu1",
"age":30, "work":"Futurist"},{"name":"Paolo",
"image":"http://goo.gl/5k2oZr", "age":30, "work":"Synergist"}]
context = {"users":users, "name":name}return engine.render("profiles.html", context)
Stepusers = [
{"name":"Em", "image":"http://goo.gl/aDxeu1", "age":30,
"work":"Futurist"},{"name":"Paolo", "image":"http://goo.gl/5k2oZr", "age":30,
"work":"Synergist"}
] Define a list of dictionaries, with each dictionary object containing information about a user. It contains information name, url of the image, age, and work
context = {"users":users, "name":name}Define a conext containing the name to be highlighted, and the list of users
return engine.render("profiles.html", context) Render the template named profiles.html with the context
Step (Inside the template)<?py for user in users: ?> Loop on the elements of the list named users, each element in the list can be referred to using the user variable
<div style="height:100px;"> Create a div element in the html to contain one user element
<img src="${user['image']}" style="float:left; height:100%;"/> Place an image in the html coming from the url defined in user[‘image’]
Step (Inside the template)<?py if name==user["name"]: ?>Compare the current user’s name to the name entered in the url
<strong>Name: ${user['name']}</strong>This happens when the above condition is true, display the name as bold characters
<?py else: ?>Add an else handler that executes if condition is not met
Step (Inside the template)Name: ${user['name']}This happens when primary condition is not met, display the user’s name without any decorations
<?py #endif ?>Denote where the if statement ends
Make a Sushi MenuCreate a menu using all the sushi items in the sushilist variable
Display the image and name of the sushi
When the menu item is clicked, it should display another page containing the name, image, price, and rating of the sushi (defined in the sushilist variable)
The most creative presentation of the menu wins a prize
Activity 1pip install geventpip install bottle
Cost per Mille =• Cost per 1000 impressions• Abuse of statistics• i.e. Magic• i.e. It sucks• Not based on empirical measured data
ADVERTISING!
Eyeballscost
How many are watching me right now?How many are paying attention?How many are interested?How many are still reading this part?How about now?Now?
ROUTER ON PROMISCUOUS MODE
DEVICEs SENDING PROBE REQUESTS
PYTHON+TCPDUMP
We get this
Pilot Installation
23000Passers-by
39%viewed
10%Finished
Meh…
Map movement
Geofencing alternative
Detectionperimeter
snoop
turn off your phones when going to the lagoon