learningpython with flaskP Y L A D I E S 2 0 1 7 W O R K S H O P # 1

MALAYSIA

before we start

whypyladies

M A L A Y S I A

MALAYSIA

howpyladies

W O R K S

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pyladiesneed you!

B E P A R T O F T H E H I S T O R Y M A K E R S

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Just right before we start

@OnApp https://facebook.com/OnApp

A SHOUT OUT TO OUR VENUE SPONSOR

introduction

SIAN LERK LAUlinkedin.com/in/sianlerk

@kiawin

∗ Amateur guitarist

∗ Ex-Intern at OnApp KL

∗ UM undergraduate student (3rd year)

∗ Python newbie, 8 months old

FADHIL YAACOB@sdil

a shout out to ourpyladies mentors

ALIES YAPJANICE SHIU

PEI PEI

MALAYSIA

jom!

R UREHDYTO PYTHON*

DO.* WHY PYTHON* THE ENVIRONMENT (PART 1 & 2)* PYTHON 101* CONTROL STRUCTURES* A REAL PROGRAM

WHY* CODE IN PYTHON

EASY TO UNDERSTANDCONCISE SYNTAXMULTI-PURPOSE STRENGTH OF PYTHON

GOOGLE-ABLE!WELL SUPPORTED LIBSFAST TO DELIVER STRENGTH OF PYTHON

ENV*PYTHON ENVIRONMENT (PART 1)

# Python interactive shell$ python

# Python interactive shell # (on steroid!)$ pip install ipython$ ipython

# QUIZ: What version of python # are you currently using?

ENV* - EASIEST WAY TO PYTHON

101*PYTHON - DATA TYPES

# DECLARE-LESS TYPED>>> a = 1>>> print a1>>> type(a)<type 'int'>

101* - DATA TYPES

# MORE TYPES - '' and "">>> b = 'a'>>> c = 'abc'>>> d = "abc"# QUIZ: WHAT DATA TYPES ARE b, c and d?>>> type(b)>>> type(c)>>> type(d)101* - DATA TYPES

# MORE TYPES# bool, NoneType, float, long>>> e = True>>> f = False>>> g = None>>> h = 1.0>>> i = 1L# QUIZ: WHAT IS None?

101* - DATA TYPES

101*PYTHON - COLLECTIONS

# COLLECTION 1: LIST>>> a = [1, 2, 3]>>> b = list()>>> b.append(1)>>> b.append(2)>>> b.append(3)# QUIZ: How do we retrieve the value?# QUIZ: Is a and b same?

101* - DATA TYPES

# SAME - EQUALITY or IDENTITY?>>> a == bTrue>>> a is bFalse

# QUIZ: WHAT IS THE DIFF # BETWEEN == AND is

101* - DATA TYPES

# COLLECTION 2 - TUPLE>>> c = (1, 2, 3)>>> d = 1, 2, 3

# QUIZ: SO AGAIN, IS c SAME with d?

101* - DATA TYPES

# COLLECTION 3: dict>>> e = {1: 11, 2: 22}>>> e[1]>>> e[2]

# QUIZ: IS THIS AN array?# QUIZ: MUST THE key BE int?

101* - DATA TYPES

# COLLECTION 4: set>>> f = set()>>> f.add(1)>>> f.add(2)>>> f.add(3)

# QUIZ: WHAT IS THE DIFF # BETWEEN list AND set?

101* - DATA TYPES

101*PYTHON - CONTROL STRUCTURES

101* - DATA TYPES

# if, else, elif>>> a = 2>>> if a == 1:... print "hello"... elif a == 2:... print "world"

>>>

101* - DATA TYPES

# if, else, elif CONTINUES>>> a = 1>>> if a == 1:... print "hello"... else:... print "world"

>>>

101* - DATA TYPES

# for LOOP>>> for i in [1, 2, 3]:... print i

>>> for j in range(1,3):... print j

# QUIZ: WHAT DO YOU SEE WHEN print j

101* - DATA TYPES

# for LOOP>>> for i in (1, 2, 3):... print i

>>> for k,v in {1: 11, 2: 22}.iteritems():... print k, v

# QUIZ: WHAT DO YOU SEE WHEN print k, v

101* - DATA TYPES

# list comprehension>>> a = [1,2,3,4,5]>>> b = [i+1 for i in a]

# QUIZ: WHAT IS THE VALUE OF b?

101* - DATA TYPES

# list comprehension>>> a = [1,2,3,4,5]>>> b = [i for i in a if i % 2 == 0]

# QUIZ: WHAT IS THE VALUE OF b?

ENV*PYTHON ENVIRONMENT (PART 2)

pip∗ Package management system used to install and

manage software packages written in Python∗ Why?

Easy package installations, updating, configuring and removals with a single command

∗ Over 86,000 Python packages can be accessed through PyPI

∗ Sample commands:$ pip install flask$ pip uninstall flask

python packages∗ Mathematical Analytics: Numpy∗ DB Connectors: MySQL, MongoDB,

PostgreSQL, etc.∗ Web Frameworks: Pyramid, Django∗ Twitter API client∗ Many more…“It’s like Swiss-army toolchain”

virtualenv∗ Is an isolated working copy of Python which allows

you to work on a specific project without worry of affecting other projects

∗ Why?We might wants to maintain the package version (prefer not upgrading it to newer version)

“Do not fix things that aren’t broken”

THE BIG PICTUREPython3

virtualenv1 virtualenv2 virtualenv3

package1 v1

package2 v1

package3 v1

package1 v2

package2 v2

package3 v2

package1 v1

package2 v2

package3 v1

virtualenv# INSTALL VIRTUALENV$ pip install virtualenv

# CREATE A NEW VENV$ virtualenv Project1

virtualenv# ACTIVATE A VENV ON LINUXworkon Project1# ON WINDOWS$ /path/to/folder/Scripts/activate.bat

# LIST INSTALLED PACKAGES(test)$ pip freeze

PROG*A REAL PROGRAM, NOW

flask∗ Flask is a micro web framework written in Python∗ Micro framework means it does not require

particular tools or libraries and it just works

∗ Suitable for minimal website or a full featured website

∗ Many extensions freely available:User authenticationsFlask-SecurityFile UploadsDatabase

Let’s get hand dirty

∗ “Hello World!”

PROG* - HELLO WORLD!

# INSTALL FLASK MODULE$ pip install flask

# QUIZ: WHAT DO YOU SEE IN RESULT# OF THE ABOVE COMMAND

PROG* - HELLO WORLD!

# EDIT A NEW FILE USING YOUR FAVOURITE# TEXT EDITOR$ vim hello.py

PROG* - HELLO WORLD!

# KEY IN THE FOLLOWING INTO THE FILEfrom flask import Flaskapp = Flask(__name__)

@app.route("/")def hello(): return "Hello World!"

NOOO WAY… R U KIDDING ME?

CONGRATULATIONS!U HV COMPLETED

A WORKING PROGRAM WEB SERVICE

# LET’S START THE WEB SERVICE$ export FLASK_APP=hello.py$ flask run

# IF WINDOWS$ set FLASK_APP=hello.py$ flask run

# QUIZ: WHAT’S NEXT?

PROG* - HELLO WORLD!

localhost:5000

BEAM ME UP, SCOTTY

Hello World!

SIMPLICITYProgramming can be easy and fun

(Using python)

PROG*WHAT’S NEXT? MOOOOOOORE~

localhost:5000

BEAM ME UP, SCOTTY… AGAIN

Not Hello World!

localhost:5000/hello

HECTOR AND THE SEARCH FOR HAPPINESS

Hello World!

PROG* - MOOOOOOORE~

# KEY IN THE FOLLOWING INTO THE FILEfrom flask import Flaskapp = Flask(__name__)

@app.route("/")def index(): return "Not Hello World!"

@app.route("/hello")def hello(): return "Hello World!"

# QUIZ: MUST THE ROUTE NAME SAME WITH # THE METHOD NAME?

PROG* - MOOOOOOOORE~

# QUIZ: CAN I DON’T RESTART FLASK# EVERY TIME I MODIFY MY FILE?$ export FLASK_DEBUG=1$ flask run

# QUIZ: WHAT IS THE COMMAND IF YOU USE# WINDOWS?

PROG* - MOOOOOOORE~

# KEY IN THE FOLLOWING INTO THE FILEfrom flask import Flaskapp = Flask(__name__)

@app.route("/")def index(): return "Index!"

@app.route("/user/<username>")def user(username): return "Hello %s!" % username

# QUIZ: WHAT HAPPEN WHEN YOU VISIT# http://localhost:5000/user

localhost:5000/user/kiawin

WHO AM I

Hello kiawin!

PROG* - MOOOOOOORE~

# FRUIT TIME!from flask import Flaskapp = Flask(__name__)

@app.route("/fruit/<fruit_name>")def fruit(fruit_name): if fruit_name in ["durian", "jackfruit"]: return "Nooooo..." else: return "Yummy..."

# QUIZ: WHAT HAPPEN IF YOU VISIT # http://localhost:5000/

localhost:5000/fruit/durian

KING OF FRUITS

Nooooo...

localhost:5000/fruit/mangosteen

HOW ABOUT MANGOSTEEN

Yummy...

localhost:5000/fruit/DURIAN

WHAT IF?

Nooooo...

PROG* - MOOOOOOORE~

# FrUiT TiMe!from flask import Flaskapp = Flask(__name__)

@app.route("/fruit/<fruit_name>")def fruit(fruit_name): if fruit_name.lower() in ["durian", "jackfruit"]: return "Nooooo..." else: return "Yummy..."

STUFF*SLIDESslideshare.net/kiawin/learning-python-with-flask

SOURCEflask.pocoo.org/docs/0.12/quickstart

Q&A*ASK US ANYTHING