Python Code Camp for Professionals 4/4

MongoDB
• Much fasterthan SQL databases
• No needto learnquery languages*and setups
• Easier toscale whendesignedproperly

Install pymongo
pip install pymongo
easy_install pymongo

Hello World
from pymongo import MongoClient
client = MongoClient("localhost", 27017)
db = client.databasename

Step
from pymongo import MongoClient
Import MongoClient from pymongo
client = MongoClient("localhost", 27017)
Connect to the mongodb server at the IP address and port defined
db = client.databasename
Access a specific database in the mongodb server
collection = db.collectionname
Access a specific collection (table in SQL) in the selected db

Basic DB Operations
•Create
•Read
•Update
•Delete

Create
@route("/register", method="POST")
def newuser():
username = request.forms.get("username")
password = request.forms.get("password")
email = request.forms.get("email")
userdata = {"name":username, "password":password, "email":email}
try:
db.users.save(userdata)
except:
return {"status":"ERROR"}
return {"status":"OK"}

Step
Get the username, password, email to data from the forms
userdata = {"name":username, "password":password,
"email":email}
Create a dictionary with the data obtained above
try:
Setup anexception handler

Step
db.users.save(userdata)
Save the dictionary to the users collection in the db we connected before
except:
Start of the exception block. Thiswill execute when the db save fails

Read
@route("/user/list")
def listuser():
usercursor = db.users.find({},{"_id":False})
users = list(usercursor)
return {"users":users}

Step
usercursor = db.users.find({},{"_id":False})
Find allentries 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 jsonobject
return {"users":users}
Return the list of users to the browser

The Query Format
db.collectionname.find(filter,projection)
Filter is the expression that needs to be true an element to be included
Examples:
• {} = 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 thanor equal to 30
See more filter operators here: https://docs.mongodb.com/manual/reference/operator/query/

The Query Format
db.collectionname.find(filter,projection)
Projection controls what fields will be shown, done by setting field names True or False
Examples:
{“name”:True}
{“_id”:False}

Inputs in Bottle
Via POST body
@route('/login', method="POST")
def login():
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 1
Create a calculatorapi:
http://localhost:8001/operation/operand1/operand2
will return the value of
operand1 <operation> operand2
Example:
/subtraction/10/2 will output 8

Common Return TYPES
PlainText
Similar to whatwe were doing earlier

Common Return TYPES
Binary
Whenreturning fileslike images, video, audio, pdfs…

Common Return TYPES
JSON
The common return type for APIs
Example: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 TYPES
HTML
Returnweb 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/apple-
touch-icon@2.png?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" />

Returning JSON Object
JSON
Simplyreturn a dictionary or list
@route("/json")
def jason():
return {"lastname":"bourne", "alias":"David Webb"}

Returning Static HTML
HTML
Use static_file from bottle
@route("/loginpage")
def loginpage():
return static_file("login.html", root=".")

Testing the POST Handler
Visit localhost:8081/loginpage
Type your nameand use any of theseas passwordg
gloopgroup, devconph, adventuretime
Click submit

The POST Request Cycle
<form action="/login" method="POST">
Method dictates what kind of request happens when submitted
Action 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 inputthat willbe associatedto the password field
<input type="submit">
Adds a button that submits the form whenclicked

Returning Dynamic HTML
HTML
Use a templatingengine:
• Library thatcan substitutevariables intoa templatequickly and cleanly
• Isolates thedesigner’s job of designing and thecoder’s job of coding

Install Tenjin
pip install tenjin
easy_install tenjin

Using Tenjin
from gevent import monkey;
monkey.patch_all()
from bottle import run, route, request
import tenjin
from 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>

Step
from gevent import monkey;
monkey.patch_all()
from bottle import run, route, request
import tenjin
from tenjin.helpers import *
Import alllibraries, 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

Step
context = {"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 avariable named word
letters = list(word)
Convert the text string into a listobject. From a string “word”, it becomes a list [“w”, “o”, “r”, “d”]

Step
context = {"letters":letters}
Define a context variable, which contains the listof 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

<?py for letter in letters: ?>
Loop on the elements of the list named letters
<h3>${letter}</h3><br>
Display the element letter along with the html
<?py #endfor ?>
Denote where the loop ends inthe template
<a href="/greet/${word}">greet ${word}</a>
Create a link that willcall 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)

Step
users = [
{"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 objectcontaining 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 behighlighted, and the list of users
return engine.render("profiles.html", context)
Render the template named profiles.html with the context

<?py for user in users: ?>
Loop on the elements of the list named users, each element in the listcan 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’]

<?py if name==user["name"]: ?>
Compare the current user’s name to the name entered in the url
<strong>Name: ${user['name']}</strong>
Thishappens when the above condition istrue, display the name asbold characters
<?py else: ?>
Add an else handler that executes if condition is not met

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 Menu
Create a menu using allthe sushiitems in the sushilistvariable
Display the image and name of the sushi
When the menu item is clicked, it should display another page containingthe name, image, price, and
rating of the sushi(defined in the sushilistvariable)
The most creative presentation of the menu wins aprize

Activity 1
pip install gevent
pip 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!
Eyeballs
cost

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?

Python Code Camp for Professionals 4/4

ROUTER ON
PROMISCUOUS MODE
DEVICEs SENDING
PROBE REQUESTS

Pilot Installation
23000
Passers-by
39%
viewed
10%
Finished

Geofencing alternative
Detection
perimeter

turn off your phones
when going to the lagoon

Python Code Camp for Professionals 4/4

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Python Code Camp for Professionals 4/4

Editor's Notes