Planet Python

To request addition or removal: Open an issue on github or e-mail planet at python.org (note, responses can take up to a few days) · December 13, 2017 06:05 AM

pip install Flask-WTF
<doctype html>
<head>
    <title>Flask Music Database</title>
</head>

<h2>Flask Music Database</h2>
# forms.py

from wtforms import Form, StringField, SelectField

class MusicSearchForm(Form):
    choices = [('Artist', 'Artist'),
               ('Album', 'Album'),
               ('Publisher', 'Publisher')]
    select = SelectField('Search for music:', choices=choices)
    search = StringField('')
# main.py

from app import app
from db_setup import init_db, db_session
from forms import MusicSearchForm
from flask import flash, render_template, request, redirect
from models import Album

init_db()

@app.route('/', methods=['GET', 'POST'])
def index():
    search = MusicSearchForm(request.form)
    if request.method == 'POST':
        return search_results(search)

    return render_template('index.html', form=search)

@app.route('/results')
def search_results(search):
    results = []
    search_string = search.data['search']

    if search.data['search'] == '':
        qry = db_session.query(Album)
        results = qry.all()

    if not results:
        flash('No results found!')
        return redirect('/')
    else:
        # display results
        return render_template('results.html', results=results)

if __name__ == '__main__':
    app.run()
{% macro render_field(field) %}
    <dt>{{ field.label }}
    <dd>{{ field(**kwargs)|safe }}
    {% if field.errors %}
        <ul class=errors>
        {% for error in field.errors %}
            <li>{{ error }}</li>
        {% endfor %}
        </ul>
    {% endif %}
    </dd>
{% endmacro %}
<doctype html>
<head>
    <title>Flask Music Database</title>
</head>

<h2>Flask Music Database</h2>

{% from "_formhelpers.html" import render_field %}
<form method=post>
  <dl>
    {{ render_field(form.select) }}
    <p>
    {{ render_field(form.search) }}
  </dl>
  <p><input type=submit value=Search>
</form>
@app.route('/', methods=['GET', 'POST'])
def index():
    search = MusicSearchForm(request.form)
    if request.method == 'POST':
        return search_results(search)

    return render_template('index.html', form=search)
<doctype html>
<head>
    <title>Flask Music Database</title>
</head>

<h2>Flask Music Database</h2>

{% with messages = get_flashed_messages() %}
  {% if messages %}
    <ul class=flashes>
    {% for message in messages %}
      <li>{{ message }}</li>
    {% endfor %}
    </ul>
  {% endif %}
{% endwith %}

{% from "_formhelpers.html" import render_field %}
<form method=post>
  <dl>
    {{ render_field(form.select) }}
    <p>
    {{ render_field(form.search) }}
  </dl>
  <p><input type=submit value=Search>
</form>
$ sudo qubes-dom0-update --enablerepo=qubes-dom0-current-testing
$ sudo qubes-dom0-update qubes-template-fedora-26

secure_copy_sequence = “Mod-c”;
secure_paste_sequence = “Mod-v”;

iwlmvm
iwlwifi

pip install flask-sqlalchemy
# db_creator.py

from sqlalchemy import create_engine, ForeignKey
from sqlalchemy import Column, Date, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship, backref

engine = create_engine('sqlite:///mymusic.db', echo=True)
Base = declarative_base()

class Artist(Base):
    __tablename__ = "artists"

    id = Column(Integer, primary_key=True)
    name = Column(String)

    def __init__(self, name):
        """"""
        self.name = name

    def __repr__(self):
        return "<Artist: {}>".format(self.name)

class Album(Base):
    """"""
    __tablename__ = "albums"

    id = Column(Integer, primary_key=True)
    title = Column(String)
    release_date = Column(Date)
    publisher = Column(String)
    media_type = Column(String)

    artist_id = Column(Integer, ForeignKey("artists.id"))
    artist = relationship("Artist", backref=backref(
        "albums", order_by=id))

    def __init__(self, title, release_date, publisher, media_type):
        """"""
        self.title = title
        self.release_date = release_date
        self.publisher = publisher
        self.media_type = media_type

# create tables
Base.metadata.create_all(engine)
2017-12-08 18:36:43,290 INFO sqlalchemy.engine.base.Engine SELECT CAST('test plain returns' AS VARCHAR(60)) AS anon_1
2017-12-08 18:36:43,291 INFO sqlalchemy.engine.base.Engine ()
2017-12-08 18:36:43,292 INFO sqlalchemy.engine.base.Engine SELECT CAST('test unicode returns' AS VARCHAR(60)) AS anon_1
2017-12-08 18:36:43,292 INFO sqlalchemy.engine.base.Engine ()
2017-12-08 18:36:43,294 INFO sqlalchemy.engine.base.Engine PRAGMA table_info("artists")
2017-12-08 18:36:43,294 INFO sqlalchemy.engine.base.Engine ()
2017-12-08 18:36:43,295 INFO sqlalchemy.engine.base.Engine PRAGMA table_info("albums")
2017-12-08 18:36:43,295 INFO sqlalchemy.engine.base.Engine ()
2017-12-08 18:36:43,296 INFO sqlalchemy.engine.base.Engine 
CREATE TABLE artists (
	id INTEGER NOT NULL, 
	name VARCHAR, 
	PRIMARY KEY (id)
)

2017-12-08 18:36:43,296 INFO sqlalchemy.engine.base.Engine ()
2017-12-08 18:36:43,315 INFO sqlalchemy.engine.base.Engine COMMIT
2017-12-08 18:36:43,316 INFO sqlalchemy.engine.base.Engine 
CREATE TABLE albums (
	id INTEGER NOT NULL, 
	title VARCHAR, 
	release_date DATE, 
	publisher VARCHAR, 
	media_type VARCHAR, 
	artist_id INTEGER, 
	PRIMARY KEY (id), 
	FOREIGN KEY(artist_id) REFERENCES artists (id)
)

2017-12-08 18:36:43,316 INFO sqlalchemy.engine.base.Engine ()
2017-12-08 18:36:43,327 INFO sqlalchemy.engine.base.Engine COMMIT
# app.py

from flask import Flask
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///mymusic.db'
app.secret_key = "flask rocks!"

db = SQLAlchemy(app)
# models.py 

from app import db

class Artist(db.Model):
    __tablename__ = "artists"

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String)

    def __init__(self, name):
        """"""
        self.name = name

    def __repr__(self):
        return "<Artist: {}>".format(self.name)

class Album(db.Model):
    """"""
    __tablename__ = "albums"

    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String)
    release_date = db.Column(db.Date)
    publisher = db.Column(db.String)
    media_type = db.Column(db.String)

    artist_id = db.Column(db.Integer, db.ForeignKey("artists.id"))
    artist = db.relationship("Artist", backref=db.backref(
        "albums", order_by=id), lazy=True)

    def __init__(self, title, release_date, publisher, media_type):
        """"""
        self.title = title
        self.release_date = release_date
        self.publisher = publisher
        self.media_type = media_type
# db_setup.py

from sqlalchemy import create_engine
from sqlalchemy.orm import scoped_session, sessionmaker
from sqlalchemy.ext.declarative import declarative_base

engine = create_engine('sqlite:///mymusic.db', convert_unicode=True)
db_session = scoped_session(sessionmaker(autocommit=False,
                                         autoflush=False,
                                         bind=engine))
Base = declarative_base()
Base.query = db_session.query_property()

def init_db():
    import models
    Base.metadata.create_all(bind=engine)
# test.py

from app import app
from db_setup import init_db

init_db()

@app.route('/')
def test():
    return "Welcome to Flask!"

if __name__ == '__main__':
    app.run()
FLASK_APP=test.py flask run
pip install virtualenv
virtualenv musicdb
cd musicdb
source bin/activate
Scripts/activate
pip install flask
Collecting flask
Downloading Flask-0.12.2-py2.py3-none-any.whl (83kB)
100% |████████████████████████████████| 92kB 185kB/s
Collecting itsdangerous&gt;=0.21 (from flask)
Downloading itsdangerous-0.24.tar.gz (46kB)
100% |████████████████████████████████| 51kB 638kB/s
Collecting Jinja2&gt;=2.4 (from flask)
Downloading Jinja2-2.10-py2.py3-none-any.whl (126kB)
100% |████████████████████████████████| 133kB 277kB/s
Collecting Werkzeug&gt;=0.7 (from flask)
Downloading Werkzeug-0.12.2-py2.py3-none-any.whl (312kB)
100% |████████████████████████████████| 317kB 307kB/s
Collecting click&gt;=2.0 (from flask)
Downloading click-6.7-py2.py3-none-any.whl (71kB)
100% |████████████████████████████████| 71kB 414kB/s
Collecting MarkupSafe&gt;=0.23 (from Jinja2&gt;=2.4-&gt;flask)
Building wheels for collected packages: itsdangerous
Running setup.py bdist_wheel for itsdangerous ... done
Stored in directory: /home/mdriscoll/.cache/pip/wheels/fc/a8/66/24d655233c757e178d45dea2de22a04c6d92766abfb741129a
Successfully built itsdangerous
Installing collected packages: itsdangerous, MarkupSafe, Jinja2, Werkzeug, click, flask
Successfully installed Jinja2-2.10 MarkupSafe-1.0 Werkzeug-0.12.2 click-6.7 flask-0.12.2 itsdangerous-0.24
# test.py

from flask import Flask

app = Flask(__name__)

@app.route('/')
def test():
    return "Welcome to Flask!"
FLASK_APP=test.py flask run
* Serving Flask app "test"
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
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$ virtualenv -p <path-to-python-to-use> ~/virtualenvs/pytip

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$ psql
psql (9.6.5, server 9.6.2)
Type "help" for help.

# create database pytip;
CREATE DATABASE
# create database pytip_test;
CREATE DATABASE

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export DATABASE_URL='postgres://postgres:password@localhost:5432/pytip'
# twitter
export CONSUMER_KEY='xyz'
export CONSUMER_SECRET='xyz'
export ACCESS_TOKEN='xyz'
export ACCESS_SECRET='xyz'
# if deploying it set this to 'heroku'
export APP_LOCATION=local

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unset DATABASE_URL
unset CONSUMER_KEY
unset CONSUMER_SECRET
unset ACCESS_TOKEN
unset ACCESS_SECRET
unset APP_LOCATION

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$ source ~/virtualenvs/pytip/bin/activate

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$ git clone https://github.com/pybites/pytip && cd pytip
$ pip install -r requirements.txt

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$ python tasks/import_tweets.py

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$ psql

\c pytip

pytip=# \dt
          List of relations
 Schema |   Name   | Type  |  Owner
--------+----------+-------+----------
 public | hashtags | table | postgres
 public | tips     | table | postgres
(2 rows)

pytip=# select count(*) from tips;
 count
-------
   222
(1 row)

pytip=# select count(*) from hashtags;
 count
-------
    27
(1 row)

pytip=# \q

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$ pytest
========================== test session starts ==========================
platform darwin -- Python 3.6.2, pytest-3.2.3, py-1.4.34, pluggy-0.4.0
rootdir: realpython/pytip, inifile:
collected 5 items

tests/test_tasks.py .
tests/test_tips.py ....

========================== 5 passed in 0.61 seconds ==========================

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$ python app.py

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from sqlalchemy import Column, Sequence, Integer, String, DateTime
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()

class Hashtag(Base):
    __tablename__ = 'hashtags'
    id = Column(Integer, Sequence('id_seq'), primary_key=True)
    name = Column(String(20))
    count = Column(Integer)

    def __repr__(self):
        return "<Hashtag('%s', '%d')>" % (self.name, self.count)

class Tip(Base):
    __tablename__ = 'tips'
    id = Column(Integer, Sequence('id_seq'), primary_key=True)
    tweetid = Column(String(22))
    text = Column(String(300))
    created = Column(DateTime)
    likes = Column(Integer)
    retweets = Column(Integer)

    def __repr__(self):
        return "<Tip('%d', '%s')>" % (self.id, self.text)

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def get_hashtags():
    return session.query(Hashtag).order_by(Hashtag.name.asc()).all()

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def add_hashtags(hashtags_cnt):
    for tag, count in hashtags_cnt.items():
        session.add(Hashtag(name=tag, count=count))
    session.commit()

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TAG = re.compile(r'#([a-z0-9]{3,})')

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def get_hashtag_counter(tips):
    blob = ' '.join(t.text.lower() for t in tips)
    cnt = Counter(TAG.findall(blob))

    if EXCLUDE_PYTHON_HASHTAG:
        cnt.pop('python', None)

    return cnt

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@route('/')
@route('/<tag>')
@view('index')
def index(tag=None):
    tag = tag or request.query.get('tag') or None
    tags = get_hashtags()
    tips = get_tips(tag)

    return {'search_tag': tag or '',
            'tags': tags,
            'tips': tips}

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@route('/static/<filename:path>')
def send_static(filename):
    return static_file(filename, root='static')

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if os.environ.get('APP_LOCATION') == 'heroku':
    run(host="0.0.0.0", port=int(os.environ.get("PORT", 5000)))
else:
    run(host='localhost', port=8080, debug=True, reloader=True)

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% for tag in tags:
  <a style="font-size: {{ tag.count/10 + 1 }}em;" href="/{{ tag.name }}">#{{ tag.name }}</a>&nbsp;&nbsp;
% end

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% for tip in tips:
  <div class='tip'>
    <pre>{{ !tip.text }}</pre>
    <div class="mui--text-dark-secondary"><strong>{{ tip.likes }}</strong> Likes / <strong>{{ tip.retweets }}</strong> RTs / {{ tip.created }} / <a href="https://twitter.com/python_tip/status/{{ tip.tweetid }}" target="_blank">Share</a></div>
  </div>
% end

Vagrant.configure("2") do |config|
 config.vm.box = "bento/ubuntu-16.04"

 config.vm.network "forwarded_port", guest: 5000, host: 5000

 config.vm.provision "ansible_local" do |a|
   a.playbook = "setup.yml"
 end
end
---
- hosts: all
  become: yes # This means that all tasks will be executed with sudo
  tasks:
   - name: Install Python 3.6
     apt:
       name: python3.6
       state: present
       update_cache: yes
TASK [Install Python 3.6] ******************************************************

fatal: [default]: FAILED! => {"changed": false, "msg": "No package matching 'python3.6' is available"}

       to retry, use: --limit @/vagrant/setup.retry
- name: Add key for jonathonf PPA
  apt_key:
    keyserver: keyserver.ubuntu.com
    id: 4AB0F789CBA31744CC7DA76A8CF63AD3F06FC659
    state: present

- name: Add jonathonf PPA
  apt_repository:
    repo: deb http://ppa.launchpad.net/jonathonf/python-3.6/ubuntu xenial main
    state: present
PLAY RECAP *********************************************************************
default                    : ok=4    changed=3    unreachable=0    failed=0
Flask==0.12
- name: Install pip3
  apt:
    name: python3-pip
    state: present
    update_cache: yes

- name: Install 'virtualenv' package
  pip:
    name: virtualenv
    executable: pip3

- name: Create virtualenv
  become: no
  pip:
    virtualenv: "/home/vagrant/venv"
    virtualenv_python: python3.6
    requirements: "/vagrant/requirements.txt"
---
- hosts: all
  become: yes # This means that all tasks will be executed with sudo
  vars:
    venv_path: "/home/vagrant/venv"
    requirements_path: "/vagrant/requirements.txt"
 tasks:
… snip … 
  - name: Create virtualenv
    become: no
    pip:
      virtualenv: "{{ venv_path }}"
      virtualenv_python: python3.6
      requirements: "{{ requirements_path }}"
- name: Add key for jonathanf PPA
  apt_key:
    keyserver: keyserver.ubuntu.com
    id: 4AB0F789CBA31744CC7DA76A8CF63AD3F06FC659
    state: present

... etc ...
---
- hosts: all
  become: yes # This means that all tasks will be executed with sudo
  vars:
    venv_path: "/home/vagrant/venv"
    requirements_path: "/vagrant/requirements.txt"
  roles:
    - {role: python}
from flask import Flask
app = Flask(__name__)

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

if __name__ == '__main__':
    app.run(host='0.0.0.0', debug=True)

Planet Python

December 13, 2017

Serving HTML Files

Adding a Search Form

Updating the Main Application

Updating the Results Functionality

Wrapping Up

Other Articles in the Series

Related Readings

December 12, 2017

About PyCon Namibia

PyCons in Africa

Be a Pythonista, not a tourist

About the travel fund

How to install Qubes on the latest UEFI systems?

First step after installing Qubes

How to modify the copy-paste between domains shortcuts?

Fixing the wireless driver issue in suspend/resume

Backstory:

Creating a Database

Using Flask-SQLAlchemy

Wrapping Up

Download Code

Other Articles in the Series

Related Readings

Getting Setup

Getting Started with Flask

Wrapping Up

Other Articles in the Series

December 11, 2017

Project Setup

Implementation Details

The DB and SQLAlchemy

Query the Twitter API

Make a Simple web app with Bottle

Bottle Templates

Add tests with pytest

Code quality matters – Better Code Hub

Conclusion and Learning

We Challenge You

Contact Info

Getting Started

Provisioning a VM with Ansible

Trouble in Paradise

Running Code from PyCharm