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Showing posts with label flask. Show all posts
Showing posts with label flask. Show all posts

Monday, September 9, 2019

Python 3.7.3 : Using the flask - part 018.

In this tutorial, I will show you how to fix auto increment in Flask SQLAlchemy.
The old source code for the user model from the server.py was this:
class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True)
    password = db.Column(db.String(120), unique=True)
    email = db.Column(db.String(120), unique=True)
    gender = db.Column(db.String(5), unique=True)
    work = db.Column(db.String(33), unique=True)
    city = db.Column(db.String(15), unique=True)
The server.sqlite will be this:
[mythcat@desk my_flask]$ sqlite3 server.sqlite 
SQLite version 3.26.0 2018-12-01 12:34:55
Enter ".help" for usage hints.
sqlite> .schema
CREATE TABLE user (
 id INTEGER NOT NULL, 
 username VARCHAR(80), 
 password VARCHAR(120), 
 email VARCHAR(120), 
 gender VARCHAR(5), 
 work VARCHAR(33), 
 city VARCHAR(15), 
 PRIMARY KEY (id), 
 UNIQUE (username), 
 UNIQUE (password), 
 UNIQUE (email), 
 UNIQUE (gender), 
 UNIQUE (work), 
 UNIQUE (city)
);
CREATE TABLE alembic_version (
 version_num VARCHAR(32) NOT NULL, 
 CONSTRAINT alembic_version_pkc PRIMARY KEY (version_num)
);
CREATE TABLE sqlite_stat1(tbl,idx,stat);
sqlite> ^Z 
If you want to change the id into auto increment then you need to follow this steps:
class User(db.Model):
    __tablename__ = 'user'
    __table_args__ = {'sqlite_autoincrement': True}
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True)
    password = db.Column(db.String(120), unique=True)
    email = db.Column(db.String(120), unique=True)
    gender = db.Column(db.String(5), unique=True)
    work = db.Column(db.String(33), unique=True)
    city = db.Column(db.String(15), unique=True)
Delete the server.sqlite file or rename it.
Open python3 and create a new server.sqlite file:
[mythcat@desk my_flask]$ python3
Python 3.7.4 (default, Jul  9 2019, 16:32:37) 
[GCC 9.1.1 20190503 (Red Hat 9.1.1-1)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from server import db
>>> db.create_all()
>>> db.engine.table_names()
['sqlite_sequence', 'user']
>>> 
[5]+  Stopat                  python3 
Open the new file to see the changes:
[mythcat@desk my_flask]$ sqlite3 server.sqlite 
SQLite version 3.26.0 2018-12-01 12:34:55
Enter ".help" for usage hints.
sqlite> .schema
CREATE TABLE user (
 id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, 
 username VARCHAR(80), 
 password VARCHAR(120), 
 email VARCHAR(120), 
 gender VARCHAR(5), 
 work VARCHAR(33), 
 city VARCHAR(15), 
 UNIQUE (username), 
 UNIQUE (password), 
 UNIQUE (email), 
 UNIQUE (gender), 
 UNIQUE (work), 
 UNIQUE (city)
);
CREATE TABLE sqlite_sequence(name,seq);
sqlite>  

Tuesday, August 27, 2019

Python 3.7.3 : Using the flask - part 017.

Today I make some changes with my server.py and database and solve some issues, see old version at my old tutorial.
Firt issue was start script.
I create a linux script named start_server.sh to run the flask run command:
[mythcat@desk my_flask]$ ./start_server.sh 
I update the User with new fiels:
class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True)
    password = db.Column(db.String(120), unique=True)
    email = db.Column(db.String(120), unique=True)
    gender = db.Column(db.String(5), unique=True)
    work = db.Column(db.String(33), unique=True)
    city = db.Column(db.String(15), unique=True)
Let's see how I deal with this versus database and migrate process.
[mythcat@desk my_flask]$ rm server.sqlite 
[mythcat@desk my_flask]$ python3
Python 3.7.4 (default, Jul  9 2019, 16:32:37) 
[GCC 9.1.1 20190503 (Red Hat 9.1.1-1)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from server import db
>>> db.create_all()
>>> db.engine.table_names()
['user']
>>> exit()
[mythcat@desk my_flask]$ ls server.sqlite 
server.sqlite
[mythcat@desk my_flask]$ sqlite3 server.sqlite 
SQLite version 3.26.0 2018-12-01 12:34:55
Enter ".help" for usage hints.
sqlite> .tables
user
sqlite> .schema user
CREATE TABLE user (
        id INTEGER NOT NULL, 
        username VARCHAR(80), 
        password VARCHAR(120), 
        email VARCHAR(120), 
        gender VARCHAR(5), 
        work VARCHAR(33), 
        city VARCHAR(15), 
        PRIMARY KEY (id), 
        UNIQUE (username), 
        UNIQUE (password), 
        UNIQUE (email), 
        UNIQUE (gender), 
        UNIQUE (work), 
        UNIQUE (city)
);
I got a strange error:
sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) duplicate column name: city
I fix it with this , but I'm not sure if the right way:
[mythcat@desk my_flask]$ rm migrations/ -r -f 
[mythcat@desk my_flask]$ python3 server.py db init 
  Creating directory /home/mythcat/project_github/my_flask/migrations ... done
  Creating directory /home/mythcat/project_github/my_flask/migrations/versions ... done
  Generating /home/mythcat/project_github/my_flask/migrations/script.py.mako ... done
  Generating /home/mythcat/project_github/my_flask/migrations/env.py ... done
  Generating /home/mythcat/project_github/my_flask/migrations/alembic.ini ... done
  Generating /home/mythcat/project_github/my_flask/migrations/README ... done
  Please edit configuration/connection/logging settings in '/home/mythcat/project_github/my_flask/migrations/alembic.ini'
  before proceeding.
[mythcat@desk my_flask]$ python3 server.py db migrate
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.env] No changes in schema detected.
[mythcat@desk my_flask]$ python3 server.py db upgrade
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.

Sunday, August 25, 2019

Python 3.7.3 : Using the flask - part 016.

Today I tested a new feature of Flask version 1.1.1.
[mythcat@desk my_flask]$ pip list | grep Flask
Flask                    1.1.1            
Flask-Login              0.4.1            
Flask-Mail               0.9.1            
Flask-Migrate            2.5.2            
Flask-Script             2.0.6            
Flask-SQLAlchemy         2.4.0            
Flask-WTF                0.14.2 
This feature will remove the jsonify python module.
Let's start the blueprint blue_test:
[mythcat@desk my_flask]$ export FLASK_APP=blue_test
[mythcat@desk my_flask]$ flask run 
 * Serving Flask app "blue_test"
 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
The output is this:
 {"result":"This is main page!"}
Into my blue_test folder I will remove this jsonify python module:
[
mythcat@desk my_flask]$ cd blue_test/
[mythcat@desk blue_test]$ ll
total 40
-rw-rw-r--. 1 mythcat mythcat  192 Aug 23 11:02 extensions.py
-rw-rw-r--. 1 mythcat mythcat 1826 Aug 23 11:02 forms.py
-rw-rw-r--. 1 mythcat mythcat  701 Aug 23 12:03 __init__.py
-rw-rw-r--. 1 mythcat mythcat 1491 Aug 23 11:02 models.py
drwxrwxr-x. 2 mythcat mythcat  184 Aug 25 14:36 __pycache__
-rw-rw-r--. 1 mythcat mythcat 1050 Aug 23 11:02 routes.py
-rw-rw-r--. 1 mythcat mythcat  142 Aug 23 11:02 settings.py
-rw-rw-r--. 1 mythcat mythcat   34 Aug 23 11:02 start.bat
drwxrwxr-x. 2 mythcat mythcat   81 Aug 23 11:02 templates
-rw-rw-r--. 1 mythcat mythcat 8192 Aug 23 11:02 texts.sqlite
-rw-rw-r--. 1 mythcat mythcat  677 Aug 23 11:02 views.py 
The routes.py will have these changes:
#from flask import Blueprint, jsonify, request
# new flask
from flask import Blueprint, request
...
def home():
    #return jsonify({'result' : 'This is main page!'})
    #this is the new source code:
    return {'result' : 'This is main page!'} 
The next step is to find all jsonify word into my source code using the grep tool and make changes:
[mythcat@desk my_flask]$ grep -nr jsonify *
Binary file blue_test/__pycache__/views.cpython-37.pyc matches
blue_test/views.py:3:from flask import Blueprint, jsonify, request
blue_test/views.py:20:    return jsonify ({'texts':texts})
blue_test/routes.py:1:#from flask import Blueprint, jsonify, request
crud.py:1:from flask import Flask, request, jsonify
crud.py:57:    return jsonify(new_user)
crud.py:64:    return jsonify(result.data)
crud.py:70:    return user_schema.jsonify(user)
crud.py:83:    return user_schema.jsonify(user)
crud.py:92:    return user_schema.jsonify(user)
Binary file __pycache__/crud.cpython-37.pyc matches
Binary file __pycache__/server.cpython-37.pyc matches
server.py:9:from flask import jsonify
server.py:101:    #return jsonify(new_user)
server.py:109:    #return users_schema.jsonify(users)
server.py:111:    return jsonify(all_users.data)
server.py:117:    return jsonify(result.data)
server.py:122:        return jsonify([d['keyword'] for d in result.data])
server.py:132:    return user_schema.jsonify(new_user)
tserv.py:13:from flask import jsonify
tserv.py:56:    #return users_schema.jsonify(users)
tserv.py:58:    return jsonify(all_users.data)
tserv.py:69:    return user_schema.jsonify(user_post)
tserv.py:80:    return user_schema.jsonify(user_put)
tserv.py:88:    return user_schema.jsonify(user_delete)
[mythcat@desk my_flask]$  
After I make changes the result of grep is this:
[mythcat@desk my_flask]$ grep -nr jsonify *
Binary file blue_test/__pycache__/views.cpython-37.pyc matches
blue_test/routes.py:1:#from flask import Blueprint, jsonify, request
blue_test/views.py:3:#from flask import Blueprint, jsonify, request
crud.py:1:#from flask import Flask, request, jsonify
Binary file __pycache__/crud.cpython-37.pyc matches
Binary file __pycache__/server.cpython-37.pyc matches
server.py:9:#from flask import jsonify
server.py:109:    #return users_schema.jsonify(users)
tserv.py:13:#from flask import jsonify
tserv.py:56:    #return users_schema.jsonify(users) 
You can see the last version of my project here.







Saturday, August 24, 2019

Python 3.7.3 : Using the flask - part 015.

In this tutorial, I will show you how to migrate using the Database Migrations in flask project.
Because my laptop is gone I use my old Linux.
First you need to install these python modules with --user argument for Linux:
[mythcat@desk my_flask]$ pip3 install flask-migrate --user
...
[mythcat@desk my_flask]$ pip3 install flask-script --user
Let's test this new issue with server.py file by adding these python modules:
#migrate 
from flask_script import Manager
from flask_migrate import Migrate, MigrateCommand
...
# create migrate object with db 
migrate = Migrate(app, db)
# create manager 
manager = Manager(app)
# create db command for manager 
manager.add_command('db', MigrateCommand)
...
# add new columns into database 
class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True)
    email = db.Column(db.String(120), unique=True)
    gender = db.Column(db.String(5), unique=True)
    work = db.Column(db.String(33), unique=True)
    city = db.Column(db.String(15), unique=True)
...
# the default name main
if __name__ == '__main__':
    manager.run()
    app.run(debug=True)
Let's fix this migrate issue with the new command:
[mythcat@desk my_flask]$ python3 server.py db init 
  Creating directory /home/mythcat/project_github/my_flask/migrations ... done
  Creating directory /home/mythcat/project_github/my_flask/migrations/versions ... done
  Generating /home/mythcat/project_github/my_flask/migrations/script.py.mako ... done
  Generating /home/mythcat/project_github/my_flask/migrations/env.py ... done
  Generating /home/mythcat/project_github/my_flask/migrations/alembic.ini ... done
  Generating /home/mythcat/project_github/my_flask/migrations/README ... done
  Please edit configuration/connection/logging settings in '/home/mythcat/project_github/my_flask/migrations
/alembic.ini'
  before proceeding.

[mythcat@desk my_flask]$ python3 server.py db migrate
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.autogenerate.compare] Detected added column 'user.city'
INFO  [alembic.autogenerate.compare] Detected added column 'user.gender'
INFO  [alembic.autogenerate.compare] Detected added column 'user.work'
INFO  [alembic.autogenerate.compare] Detected added unique constraint 'None' on '['city']'
INFO  [alembic.autogenerate.compare] Detected added unique constraint 'None' on '['gender']'
INFO  [alembic.autogenerate.compare] Detected added unique constraint 'None' on '['work']'
  Generating /home/mythcat/project_github/my_flask/migrations/versions/ca70c42b5b7a_.py ... done

[mythcat@desk my_flask]$ python3 server.py db upgrade 
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.runtime.migration] Running upgrade  -> ca70c42b5b7a, empty message
ERROR [root] Error: No support for ALTER of constraints in SQLite dialect
The database fiels is changed by this command.
Let's see with sqlite3 tool:
[mythcat@desk my_flask]$ sqlite3 server.sqlite 
SQLite version 3.26.0 2018-12-01 12:34:55
Enter ".help" for usage hints.
sqlite> .tables
alembic_version  user           
sqlite> .schema user
CREATE TABLE user (
        id INTEGER NOT NULL, 
        username VARCHAR(80), 
        email VARCHAR(120), city VARCHAR(15), gender VARCHAR(5), work VARCHAR(33), 
        PRIMARY KEY (id), 
        UNIQUE (username), 
        UNIQUE (email)
);
You can see my source code here.

Wednesday, August 14, 2019

Python 3.7.3 : Using the flask - part 014.

Today I worked on YouTube search with flask and Google A.P.I. project.
The source code is simple to understand and you can test any A.P.I. from google using this way.
I created a new Google project with YouTube A.P.I. version 3 and with the A.P.I. key.
I use this key to connect with flask python module.
I used the isodate python module.
You can see the source code on my GitHub repo named flask_yt.
The result is this:

Friday, August 9, 2019

Python 3.7.3 : Using the flask - part 013.

Flask uses Jinga2 template engine.
The Jinga2 template engine uses the following delimiters for escaping from HTML.
We can use this:
  • {% ... %} for Statements
  • {{ ... }} for Expressions to print to the template output
  • {# ... #} for Comments not included in the template output
  • # ... ## for Line Statements
The documentation webpage comes with all information about how can be used.
I create a new HTML5 file named layout.html and I will use this like an example:
{% if current_user.is_authenticated %}
...
{% else %}
...
{% endif %}
This file can be add into another file like this:
{% extends "layout.html" %}
{% block content %}
...
{% endblock content %}
For example, my about.html webpage comes with this source code:
{% extends "layout.html" %}
{% block content %}
    

About Page

{% endblock content %}
The routes.py this webpage will have this call:
@app.route("/about")
def about():
    return render_template('about.html', title='About')
In this way, I will add more HTML5 files to the project.


Thursday, August 8, 2019

Python 3.7.3 : Using the flask - part 012.

The goal of this tutorial step is to understand how the project can use the new features and implementation of the project.
Because in the last tutorial I used the flask_mail python module, now I will add into my project structure.
One good issue is registration issue for users.
First, you need to see the full project and changes at my GitHub project.
I used the itsdangerous python module to use tokens.
Let's install this with the pip tool:
C:\Python373\Scripts>pip install itsdangerous
For registration is need to have login issues and we can use LoginManager, see the extensions.py
#use SQLAlchemy
from flask_sqlalchemy import SQLAlchemy
#use LoginManager
from flask_login import LoginManager
#create login_manager
login_manager = LoginManager()
#create db
db = SQLAlchemy()
Let's see the new User model, see the models.py:
#imports for user model
from datetime import datetime
from .extensions import db
from itsdangerous import TimedJSONWebSignatureSerializer as Serializer
from blue_test import login_manager
from flask_login import UserMixin

# import db from base folder, see dot
from .extensions import db 

#load the user by id
@login_manager.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))

# create the Texts mode
class Texts(db.Model):
    # primary key 
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(50))
    txt_content = db.Column(db.String(1000))
    
# create the User model
'''
id = id key for user
username = name
email = user email
password = user password

'''
class User(db.Model, UserMixin):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(20), unique=True, nullable=False)
    email = db.Column(db.String(120), unique=True, nullable=False)
    password = db.Column(db.String(60), nullable=False)

    def get_reset_token(self, expires_sec=1800):
        s = Serializer(app.config['SECRET_KEY'], expires_sec)
        return s.dumps({'user_id': self.id}).decode('utf-8')

    @staticmethod
    def verify_reset_token(token):
        s = Serializer(app.config['SECRET_KEY'])
        try:
            user_id = s.loads(token)['user_id']
        except:
            return None
        return User.query.get(user_id)

    def __repr__(self):
        return f"User('{self.username}', '{self.email}')"
In the blue_test folder project I created the templates folder with two HTML5 files: home.html and register.html.
I created also the forms.py file and I update with my forms: RegistrationForm,RequestResetForm, ResetPasswordForm.
#import python for create forms 
from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, SubmitField
# import python for validate forms field
from wtforms.validators import DataRequired, Length, Email, EqualTo, ValidationError
#import python files project
from .extensions import db, login_manager

class RegistrationForm(FlaskForm):
    username = StringField('Username',
                           validators=[DataRequired(), Length(min=2, max=25)])
    email = StringField('Email',
                        validators=[DataRequired(), Email()])
    password = PasswordField('Password', validators=[DataRequired()])
    confirm_password = PasswordField('Confirm Password',
                                     validators=[DataRequired(), EqualTo('password')])
    submit = SubmitField('Sign Up')

    def validate_username(self, username):
        user = User.query.filter_by(username=username.data).first()
        if user:
            raise ValidationError('That username is taken.')

    def validate_email(self, email):
        user = User.query.filter_by(email=email.data).first()
        if user:
            raise ValidationError('That email is taken.')

class RequestResetForm(FlaskForm):
    email = StringField('Email',
                        validators=[DataRequired(), Email()])
    submit = SubmitField('Password Reset')

    def validate_email(self, email):
        #get user by email
        
        if user is None:
            raise ValidationError('There is no account with that email.')

class ResetPasswordForm(FlaskForm):
    password = PasswordField('Password', validators=[DataRequired()])
    confirm_password = PasswordField('Confirm Password',
                                     validators=[DataRequired(), EqualTo('password')])
    submit = SubmitField('Reset Password')
In the __init__.py file I add this:
#import python files project
from .extensions import db, login_manager
...
    login_manager.init_app(app)
The routers.py will have the new RegistrationForm:
@api.route("/register", methods=['GET', 'POST'])
def register():
    # check if the user is authenticated
    if current_user.is_authenticated:
        return redirect(url_for('home'))
    form = RegistrationForm()
    if form.validate_on_submit():
        flash('Your account has been created!, 'success')
        return redirect(url_for('login'))
    return render_template('register.html', title='Register', form=form)
Depending on your needs, we will send and redirect these forms to the HTML files.
Depending on your needs (users, page access, ...) we will be able to write the source code further.

Wednesday, August 7, 2019

Python 3.7.3 : Using the flask - part 011.

The tutorial for today is focused on the email issue.
I will start with the new python module for flask named flask_mail.
Let's install it:
C:\Python373>cd Scripts

C:\Python373\Scripts>pip3 install flask_mail
Collecting flask_mail
...
Installing collected packages: blinker, flask-mail
Successfully installed blinker-1.4 flask-mail-0.9.1
The next source code let show you how can use this python module.
from flask import Flask 
from flask_mail import Mail, Message

app = Flask(__name__)
app.config['DEBUG'] = True
app.config['TESTING'] = False
app.config['MAIL_SERVER'] = 'smtp...'
app.config['MAIL_PORT'] = 25
app.config['MAIL_USE_TLS'] = False
app.config['MAIL_USE_SSL'] = False
#app.config['MAIL_DEBUG'] = True # debug 
app.config['MAIL_USERNAME'] = None
app.config['MAIL_PASSWORD'] = None
# this will send with the name of another@mail.com
#app.config['MAIL_DEFALT_SENDER'] = ('Another mail', 'another@mail.com')
app.config['MAIL_DEFALT_SENDER'] = None
app.config['MAIL_MAX_EMAILS'] = None # limit the messages send
#app.config['MAIL_SUPRESS_SEND'] = False # testing
app.config['MAIL_ASCII_ATTACHMENTS'] = False

# send an email with the flask application
mail = Mail(app)

@app.route('/mail')
def mail():
    #msg = Message('Hey', sender='another@mail.com')
    #msg = Message('Hey', recipients=['catafest@yahoo.com', 'another@mail.com'])
    #msg.add_recipient = ('another@mail.com')
    msg = Message('Hey', recipients=['catafest@yahoo.com'])

    # you can use body or HTML, using both wills receive the HTML first
    #msg.body = 'This is a body text message!'
    msg.html = 'This is a body text message with HTML5 tags!'

    #add a file attachment to message 
    with app.open_resource('photo.jpg') as add_file_res:
         msg.attach('photo.jpg', 'image/jpeg', add_file_res.read())
    '''
    #create a template message 
    msg = Message(
    subject ='',
    recipients=[],
    body = '',
    html = '',
    sender = '',
    cc = [],
    bcc = [],
    attachments = [],
    reply_to = [],
    date = '',
    charset = [],
    extra_headers = {'':''},
    mail_options = [],
    rcpt_options = []
    )
    '''
    #send mail
    mail.send(msg)
    return 'Message sent!'

@app.route('/bulk')
def bulk():
    users = [{'name':'Me', 'email':'another@mail.com'}]
    # open an connection 
    with mail.connect() as con:
         for user in users:
             msg = Message('Bulk message!', recipients=[user['email']]
             msg.body = 'Body message!'
             con.send(msg)
'''
# another example 
@app.route('/bulk')
def bulk():
    users = [{'name':'Me', 'email':'another@mail.com'}]
    # open an connection 
    with mail.connect() as con:
         for user in users:
             msg = Message('Bulk message!', recipients=[user.email]
             msg.body = 'Body message!'
             con.send(msg)
'''
if __name__ == '__main__':
    app.run()
You can see you need to set the settings for your mail server and then use it into flaks application.
The source code is easy to understand if you follow the commented rows.
I add also put into comments alternative examples for the template message and the bulk function.
This is the first step into sending emails with flask.
We can have a complete implementation on the project but all depends on project structure.

Tuesday, August 6, 2019

Python 3.7.3 : Using the flask - part 010.

If you read my last tutorial about flask then you understand how to use the structure flask project with views.py and models.py.
If you run it and open the browser with http://127.0.0.1:5000/texts/ the result will be this:
{"texts":[{"title":"first title","txt_content":"this is first content"},{"title":null,"txt_content":null}]}
Let's create a file .env into the base folder named my_flask and add this source code:
SECRET_KEY='secret key'
DEBUG=True
SQLALCHEMY_TRACK_MODIFICATIONS = False
SQLALCHEMY_DATABASE_URI = sqlite:///texts.sqlite
Let's create a settings.py file into blue_test folder to get these settings:
import os
from os import environ
SECRET_KEY = os.environ.get('SECRET_KEY')
SQLALCHEMY_DATABASE_URI = os.environ.get('SQLALCHEMY_DATABASE_URI')
My blue_test project comes with the old views.py and a new routes.py file with this source code:
from flask import Blueprint, jsonify, request

api = Blueprint('api', __name__)

@api.route('/')
def home():
    return jsonify({'result' : 'You are in main page!'}) 
I create an extensions.py python script to deal with the database, see the source code:
from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()
With this new python file will solve the avoid circular importing of circular dependency of importing db.
This changes can be made on models.py and views.py, like this:
# import db from base folder, see dot
from .extensions import db 
This two files views.py and routes.py come with two Blueprint's: main and api.
Into the __init__.py will need to import and register both :
from .extensions import db
from .models import Texts
from .routes import api
from .views import main
...
    app.register_blueprint(main)
    app.register_blueprint(api)
If you run it into my_flask folder with:
C:\Python373\my_flask>set FLASK_APP=blue_test

C:\Python373\my_flask>flask run
 * Serving Flask app "blue_test"
 * Environment: production
...
The result into the browser area with http://127.0.0.1:5000/ for the routes.py blueprint api will be:
{"result":"You are in main page!"}
The result into the browser area with http://127.0.0.1:5000/texts/ for the views.py blueprint main will be:
{"texts":[{"title":"first title","txt_content":"this is first content"},{"title":null,"txt_content":null}]}
This shows you how to link multiple blueprints into one project.
You can see the full project at my GitHub project.

Monday, August 5, 2019

Python 3.7.3 : Using the flask - part 009.

In this tutorial, I will show you how to use blueprints with a new type of flask project using multiple python files.
I show you just how to create the A.P.I. not the REACT front end.
Flask uses a concept of blueprints for making application components and supporting common patterns within an application or across applications. Blueprints can greatly simplify how large applications work and provide a central means for Flask extensions to register operations on applications. A Blueprint object works similarly to a Flask application object, but it is not actually an application. Rather it is a blueprint of how to construct or extend an application., see the official webpage.
In my my_flask folder, I create a blue_test folder with three python files: __init__.py, views.py, and models.py.
The __init__.py file has this source code:
from flask import Flask
from flask_sqlalchemy import SQLAlchemy

# create path for SQLAlchemy
import os
basedir = os.path.abspath(os.path.dirname(__file__))

db = SQLAlchemy()

def create_app():
    app = Flask(__name__)
    # instantiate config for SQLAlchemy
    app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
    app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + os.path.join(basedir, 'texts.sqlite')
    # init db 
    db.init_app(app)
    # avoid circular importing of circular dependency 
    from .views import main
    app.register_blueprint(main)
    return app
The views.py come with this source code:
from flask import Blueprint
from flask import jsonify, request
from . import db
from .models import Texts

main = Blueprint('main', __name__)
@main.route('/add_text', methods = ['POST'])
def add_text():
    txt_data = request.get_json()
    new_txt = Texts(title=txt_data['title'], txt_content=txt_data['txt_content'])
    db.session(new_txt)
    db.session.commit()
    # 201 status code for create successfully
    return 'Done', 201
@main.route('/texts/')
def texts():
    txt_list=Texts.query.all()
    texts=[]
    for txt in txt_list:
        texts.append({'title': txt.title, 'txt_content':txt.txt_content})
    return jsonify ({'texts':texts})
The models.py has this source code:
# import db from base folder, see dot
from . import db 

class Texts(db.Model):
    # primary key 
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(50))
    txt_content = db.Column(db.String(1000))
Use the base folder of the blue_test folder to instantiate the database named texts.sqlite with a table texts.
C:\Python373>cd my_flask

C:\Python373\my_flask>python
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 22:22:05) [MSC v.1916 64 bit (AMD6
4)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> from blue_test.models import Texts
>>> from blue_test import db, create_app
>>> db.create_all(app=create_app())
>>> exit()
If not run into the base folder then you get this error:
    from . import db
ImportError: attempted relative import with no known parent package
Now you will have a texts.sqlite file for the database.
Use this command to set FLASK_APP:
C:\Python373\my_flask>set FLASK_APP=blue_test
C:\Python373\my_flask>flask run
Now, using the postman you can test it by running the python script and call these methods.



Sunday, August 4, 2019

Python 3.7.3 : Using the flask - part 008.

The tutorial for today will show you how to understand the flash method and fix exceptions.
First, the Flask module contains a flash method which passes a message to the next request, which generally is a template.
This lets you create feedback to users of a web application is critical, from notifications and error messages to warnings and progress alerts.
This system allows us to record a message at any point within a request, then display it at the start of the next request (and only the next request), see the documentation.
You need to import the flash with:
from flask import flash
The flash function takes up to 2 arguments, a message and a category like this: flash("message", "category").
In the next example, the random range output named out will send a flash message by category.
The flash warning category will send the number get by the random and will be into a range of 1 and 3.
Flashed messages are stored in the session until they are read it.
The HTML5 page named home.html can be found at my GitHub project.
This source code will send one message by flash and show two messages into a webpage.
@app.route('/',methods = ['GET','POST'])
def home():
    # test flash message
    out = random.randint(1,10)
    if out in range(1,3):
        flash(str(out),"warning" )
    if out in range(4,6):
        flash("This is a flash test for home.html with result:","success")
    if out in range(7,10):
        flash("This is a flash test for home.html with result:","danger")  
    return render_template("home.html")
The next example shows you how to use flash and exceptions to create an output error with render_template_string.
The output exception sends by flash without an HTML5 page request.
from flask import render_template_string
...
# fix Exception error , like 404
@app.errorhandler(Exception)
def page_not_found(e):
    flash(e, type(e))  
    return render_template_string('''
      {% with messages = get_flashed_messages(with_categories=true) %}
        {% if messages %}
          {% set printed_messages = dict() %}
          {% for category, message in messages %}
            {% if message not in printed_messages %}
              
{{message}}
{% set x = printed_messages.__setitem__(message, "value") %} {% endif %} {% endfor %} {% endif %} {% endwith %} ''')
If you put a bad path URL intro the server ( http://127.0.0.1:5000/bad ) then you get the result of the exception 404:
404 Not Found: The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.
Using the flash you can create your own notification system.

Saturday, August 3, 2019

Python 3.7.3 : Using the flask - part 007.

This will be a long tutorial because will try to link some information's from the last tutorials.
First, the structure of the project can see into my GitHub project.
I create new templates and another python script named tserv.py for testing.
You can see easier how the POST method works and how to deal with a python database issue.
This script comes with an upload file feature and upload database with sqlite3 python module.
First, for upload a file we need the HTML5 file from templates folder named upload.html.
I update the base.html file to use the bootstrap framework.
import sqlite3
class UploadForm(FlaskForm):
    file = FileField()
    submit = SubmitField("submit")
    
@app.route('/upload',methods = ['GET','POST'])
def upload():
    form = UploadForm()
    
    if request.method == "POST" and form.validate():
        if form.validate_on_submit():
            file_name = form.file.data
            file_database(name = file_name.filename,data = file_name.read())
            print("File {}".format(file_name.filename))
            return render_template("upload.html", form = form)
    return render_template("upload.html", form = form)
def file_database(name,data):
    con=sqlite3.connect("file_upload.db")
    cursor = con.cursor()
    cursor.execute("""CREATE TABLE IF NOT EXISTS my_table (name TEXT, data BLOP) """)
    cursor.execute("""INSERT INTO my_table (name , data ) VALUES (?,?) """, (name, data))
    con.commit()
    cursor.close()
    con.close()
Let's run it:
python tserv.py
Into the main folder a database will be create and will fill with the file uploaded.
Now, if you want to add more we can create a download button into our UploadForm, is no need to have another python class.
First create your form tag into upload.html file and link with the python tserv.py code show bellow:
from flask import send_file
from io import BytesIO
...
@app.route('/download', methods=['GET','POST'])
def download():
    form = UploadForm()
    if request.method == "POST":
        con = sqlite3.connect("file_upload.db")
        cursor = con.cursor()
        cur_ex = cursor.execute(""" SELECT * FROM my_table """)
        for i in cur_ex.fetchall():
            name=i[0]
            data=i[1]
            break
        con.commit()
        cursor.close()
        con.close()
        return send_file(BytesIO(data), attachment_filename='test', as_attachment=True)
    return render_template("home.html", form = form)
When you run it the download button will download the first file upload into database.
This example tutorial can be more complex.
For example, you can show the database content into a new HTML file and then save with an open dialog to disk.

Friday, August 2, 2019

Python 3.7.3 : Using the flask - part 006.

Today I will show you how to use the RESTful API application with flask python module that uses HTTP requests to GET, PUT, POST and DELETE data.
When HTTP is used, as is most common, the operations (HTTP methods) available are GET, HEAD, POST, PUT, PATCH, DELETE, CONNECT, OPTIONS and TRACE.[2], see the Wikipedia article.
All of these HTTP methods will be tested with postman software.
You need to have an account and use the downloaded software in order to interrogate with these methods.
Let's see the source new code first:
@app.route("/users/", methods=['GET'])
def users():
    users = User.query.all()
    #return users_schema.jsonify(users)
    all_users = users_schema.dump(users)
    return jsonify(all_users.data)

@app.route("/users/", methods=['POST'])
def user_post(id):
    user_post = User.query.get(id)
    print(user_post)
    username = request.json['username']
    email = request.json['email']
    user_post.username = username
    user_post.email = email
    db.session.commit()
    return user_schema.jsonify(user_post)

@app.route("/users/", methods=['PUT'])
def user_put(id):
    user_put = User.query.get(id)
    print(user_put)
    username = request.json['username']
    email = request.json['email']
    user_put.username = username
    user_put.email = email
    db.session.commit()
    return user_schema.jsonify(user_put)

@app.route("/users/", methods=['DELETE'])
def user_delete(id):
    user_delete = User.query.get(id)
    print(user_delete)
    db.session.delete(user_delete)
    db.session.commit()
    return user_schema.jsonify(user_delete)
Using the postman you can test it by running the python script and call these methods at http://127.0.0.1:5000/users/.

Thursday, August 1, 2019

Python 3.7.3 : Using the flask - part 005.

In the last tutorial, I used the flask-sqlalchemy python module.
Today I will show you how to use the flask_marshmallow python module.
First, let's take a look at this python module, see the official webpage:
Flask-Marshmallow is a thin integration layer for Flask (a Python web framework) and marshmallow (an object serialization/deserialization library) that adds additional features to marshmallow, including URL and Hyperlinks fields for HATEOAS-ready APIs. It also (optionally) integrates with Flask-SQLAlchemy.
The base class User will need to be integrated with this python module:
from flask import Flask
from flask import render_template
from forms import SignUpForm
from flask import request

from flask import jsonify
from flask_sqlalchemy import SQLAlchemy
from flask_marshmallow import Marshmallow
import os
from forms import AddUser

app = Flask (__name__)
app.config['SECRET_KEY'] = 'abcdefg'
# set SQLAlchemy
basedir = os.path.abspath(os.path.dirname(__file__))
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + os.path.join(basedir, 'server.sqlite')
db = SQLAlchemy(app)
ma = Marshmallow(app)
class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True)
    email = db.Column(db.String(120), unique=True)

    def __init__(self, username, email):
        self.username = username
        self.email = email
    '''
    def __rep_(self):
        return '' % self.username
    '''
class UserSchema(ma.ModelSchema):
    class Meta:
        model = User
user_schema = UserSchema()
users_schema = UserSchema(many=True)

@app.route("/users/", methods=['GET'])
def users():
    users = User.query.all()
    #return users_schema.jsonify(users)
    all_users = users_schema.dump(users)
    return jsonify(all_users.data)

# the default name main
if __name__ == '__main__':
    app.run(debug=True)
Let's take a look at http://127.0.0.1:5000/users/ and see the result:
[
  {
    "email": "catafest@yahoo.com", 
    "id": 1, 
    "username": "catafest"
  }, 
  {
    "email": "test@test.com", 
    "id": 2, 
    "username": "user_test"
  }
]

Tuesday, July 30, 2019

Python 3.7.3 : Using the flask - part 004.

The goal of this tutorial is to interact with the database in order to use it with flask_sqlalchemy python module.
The db.Model is used to interact with the database.
A database doesn't need a primary key but if you using the flask-sqlalchemy you need to have it for each one table in order to connect it.
Let's see the database:
C:\Python373\my_flask>python
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 22:22:05) [MSC v.1916 64 bit (AMD6
4)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> from server import db
>>> db.create_all()
>>> db.engine.table_names()
['user']
Let's add some data into database on user table:
C:\Python373\my_flask>python
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 22:22:05) [MSC v.1916 64 bit (AMD6
4)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> from server import db
>>> from server import User
>>> first_user = User(username='catafest',email='catafest@yahoo.com')
>>> db.session.add(first_user)
>>> db.session.commit()
>>> test_user = User(username='test',email='test@test.com')
>>> db.session.add(test_user)
>>> db.session.commit()
Update is a simple issue.
Let's update the username test_user from test to user_test:
>>> test_user.username = 'user_test'
>>> db.session.commit()
The delete is simple like the add:
>>> db.session.delete(test_user)
>>> db.session.commit()
Let's use query:
>>> results=User.query.all()
>>> results[0].username
'catafest'
>>> results[0].email
'catafest@yahoo.com'
>>> results
The next step is an important issue because let you to see how result by content and query and filter by first result:
>>> q1 = User.query.filter_by(username='catafest')
>>> q1
...flask_sqlalchemy .basequery= ...
>>> print(q1)
SELECT user.id AS user_id, user.username AS user_username, user.email AS user_email
FROM user
WHERE user.username = ?
>>> q2 = User.query.filter_by(username='catafest').first()
>>> q2
< User 1 >
>>> print(q2)
< User 1 >
>>> print(q1.username)
Traceback (most recent call last):
  File "", line 1, in 
AttributeError: 'BaseQuery' object has no attribute 'username'
>>> print(q2.username)
catafest
>>> print(q2.username,q2.email)
catafest catafest@yahoo.com 
In this case because the first is limited to one result the print of q2 is the correct way.

Sunday, July 28, 2019

Python 3.7.3 : Using the flask - part 003.

Another tutorial with python 3.7.3 and flask python module.
In the last tutorial, I speak about some tricks and tips.
Today, I will show some steps for fixing and run with flask-sqlalchemy.
The source code from my GitHub account can be updated with this source code.
app = Flask (__name__)
app.config['SECRET_KEY'] = 'abcdefg'
# set SQLAlchemy
basedir = os.path.abspath(os.path.dirname(__file__))
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + os.path.join(basedir, 'server.sqlite')
db = SQLAlchemy(app)
ma = Marshmallow(app)
class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True)
    email = db.Column(db.String(120), unique=True)

    def __init__(self, username, email):
        self.username = username
        self.email = email
If you run it then you get this:
C:\Python373\my_flask>python
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 22:22:05) [MSC v.1916 64 bit (AMD6
4)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> from server import db
C:\Python373\lib\site-packages\flask_sqlalchemy\__init__.py:835: FSADeprecationW
arning: SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be dis
abled by default in the future.  Set it to True or False to suppress this warnin
g.
  'SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and '
You will have a database file named server.sqlite.
#app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
Let's create and show the database:
C:\Python373\my_flask>python
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 22:22:05) [MSC v.1916 64 bit (AMD6
4)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> from server import db
>>> db.create_all()
>>> db.engine.table_names()
['user']
A good approach is to create a config.py file and used into the application area.
The config.py file will have this source code:
SQLALCHEMY_TRACK_MODIFICATIONS = False
SQLALCHEMY_DATABASE_URI = 'sqlite:///' + os.path.join(basedir, 'server.sqlite')
DEBUG=True
The server.py has this source code:
...
app = Flask (__name__)
app.config.from_pyfile('config.py')
db = SQLAlchemy(app)
...

Thursday, July 25, 2019

Python 3.7.3 : Using the flask - part 002.

Let's see some tips for starting any project with flask python module.
Use these python modules to work with databases: flask-sqlalchemy and flask_marshmallow.
The Flask-SQLAlchemy is an extension for Flask that adds support for SQLAlchemy to your application.
The marshmallow is an ORM/ODM/framework-agnostic library for converting complex datatypes, such as objects, to and from native Python datatypes.
Let's install it:
C:\Python373>cd Scripts

C:\Python373\Scripts>pip install flask-sqlalchemy
Collecting flask_sqlalchemy
...
Successfully installed flask-sqlalchemy-2.4.0
C:\Python373\Scripts>pip install flask_marshmallow
Collecting flask_marshmallow
...
Successfully installed flask-marshmallow-0.10.1 marshmallow-2.19.5
C:\Python373\Scripts>pip install marshmallow-sqlalchemy
Collecting marshmallow-sqlalchemy
...
Successfully installed marshmallow-sqlalchemy-0.17.0
Use these python modules for login and authorization issues: flask-login
The Flask-Login provides user session management for Flask. It handles the common tasks of logging in, logging out, and remembering your users’ sessions over extended periods of time.
Flask-login doesn't actually have a user backend, it just handles the session machinery to help you to log in and logout users.
Flask-Login can work with user models that are based on any database system with four required items: is_authenticated, is_active, is_anonymous and get_id.
Let's install it:
C:\Python373\Scripts>pip install flask-login
Collecting flask-login
...
Successfully installed flask-login-0.4.1
This python module named python-dotenv let us to reads the key-value pair from .env file and adds them to an environment variable.
C:\Python373\Scripts>pip install python-dotenv
Collecting python-dotenv
...
Successfully installed python-dotenv-0.10.3
Flask-Login provides a UserMixin which makes it easy to create a user class, see example class User:
from flask_login import UserMixin
...
class User(UserMixin, db.Model):
Another tip is to use the get_or_404 and first_or_404 to avoid show errors on the webpage.
Reduce the passing of multiple variables to render_template, let's see the example:
from flask import render_template
...
return render_template('index.html', fn=name.first, ln=name.last, day=student.day, 
.... ')
This can de easy fix with this code to send value I want to pass:
context = {
'fn': name.first,
'ln': name.last,
'day': student.day,
...
}
return render_template('index.html', **context)
Use query to solve complex tasks.
Let's see a simple example of delete from a Student database class:
...
class Student(db.Model):
id=db.Column(db.Integer, primary_key=True)
...
country=db.Column(db.String(2))
...
Let's delete this with a query and return the number of deleted by delete_count:
del_ids= db.session.query(Student.id).filter(Student.country=='Ro')
delete_count=db.session.query(Student).filter(Student.id.in_(del_ids.subquery())).delete(synchronize_session=False)
I used two files in the main project named .env and .flaskenv:
The file .env comes with:
SQLALCHEMY_DATABASE_URI=sqlite:///db.sqlite3
SECRET_KEY = abcdef
The file .flaskenv has these lines of source code:
FLASK_ENV = development
FLASK_APP = my_flask_app
This can be used into a new file named settings.py:
import os 
SQLALCHEMY_DATABASE_URI = os.environ.get('SQLALCHEMY_DATABASE_URI')
SECRET_KEY = os.environ.get('SECRET_KEY')
SQLALCHEMY_TRACK_MODIFICATIONS = False
Using this the main flask application will start like this:
from flask import Flask
def create_my_app(config_file='settings.py'):
    app = Flask(__name__)
    app.config.from_pyfile(config_file)
    return app
There are plenty of tips and tricks that can be found based on the project in the bottle.
These are the most used.


Tuesday, July 23, 2019

Python 3.7.3 : Using the flask - part 001.

A short intro into this python module can be found at the PyPI website:
Flask is a lightweight WSGI web application framework. It is designed to make getting started quick and easy, with the ability to scale up to complex applications. It began as a simple wrapper around Werkzeug and Jinja and has become one of the most popular Python web application frameworks.

Flask offers suggestions but doesn’t enforce any dependencies or project layout. It is up to the developer to choose the tools and libraries they want to use. There are many extensions provided by the community that makes adding new functionality easy.

The reason I used a series of tutorials with this python module is the complexity of the features of this python module.
Let's briefly outline some of the essential aspects of flask programming.
  • Flask is a simple, lightweight, and minimalist web framework;
  • Flask is developed based on the Jinja2 template engine;
  • Flask depends on the Jinja template engine and the Werkzeug WSGI toolkit;
  • Flask does not provide a built-in ORM system (Object Relation Mapping);
  • in Flask web applications to perform CRUD operations on a database can be tedious (see: ORM techniques of Flask-SQLAlchemy);
  • The Flask has a simple and customizable architecture;
  • the Flask to accelerate the development of simple websites that use static content;
  • has the option to extend and customize Flask according to precise project requirements;
A list of companies using the Flask framework - who is using Flask?
The install process is very simple using the pip tool:
C:\Python373>cd Scripts

C:\Python373\Scripts>pip install flask
Collecting flask
...
Installing collected packages: itsdangerous, Werkzeug, flask
Successfully installed Werkzeug-0.15.4 flask-1.1.1 itsdangerous-1.1.0
Let's start initializing the first flask application into the server.py file:
from flask import Flask 
app = Flask (__name__)
# create a wrarp of localhost
@app.route('/')
def home():
 return 'Hello world'
# the default name main 
if __name__ == '__main__':
 app.run()
About Routing and Variable Rules.
This can change it into the server.py script like this:
@app.route('/about')
def about():
 return 'The about page'
@app.route('/blog')
def blog():
 return 'This is the blog'
The next step is the variable rule issue:
# creaza a regula variabila ( variable rules) 
# the type of the variable can be set, see int 
# @app.route('/blog/')
@app.route('/blog/')
def blogpost(blog_id):
 return 'This is the post '+str(blog_id)
To run it, just use:
C:\Python373\my_flask>python server.py
 * Serving Flask app "server" (lazy loading)
 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
   Use a production WSGI server instead.
 * Debug mode: off
 * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
The full source code can be found at my GitHub account.

Thursday, August 10, 2017

Using Flask and Flask-WTF to build websites in Python 2.7 and 3.6.2 - part 002.

This is one update of my old tutorial about Flask and python 2.7 under Linux from here.
The default install of python 2.7 and pip is very simple - read this tutorial.
First, you need to install the Flask python module under Windows 10:
C:\Python27\Scripts>pip install Flask
Collecting Flask
Downloading Flask-0.11.1-py2.py3-none-any.whl (80kB)
100% |################################| 81kB 564kB/s
Collecting click>=2.0 (from Flask)
Downloading click-6.6-py2.py3-none-any.whl (71kB)
100% |################################| 71kB 1.3MB/s
Collecting Werkzeug>=0.7 (from Flask)
Downloading Werkzeug-0.11.11-py2.py3-none-any.whl (306kB)
100% |################################| 307kB 231kB/s
Collecting Jinja2>=2.4 (from Flask)
Downloading Jinja2-2.8-py2.py3-none-any.whl (263kB)
100% |################################| 266kB 890kB/s
Collecting itsdangerous>=0.21 (from Flask)
Downloading itsdangerous-0.24.tar.gz (46kB)
100% |################################| 51kB 1.3MB/s
Collecting MarkupSafe (from Jinja2>=2.4->Flask)
Downloading MarkupSafe-0.23.tar.gz
Installing collected packages: click, Werkzeug, MarkupSafe, Jinja2, itsdangerous
, Flask
Running setup.py install for MarkupSafe ... done
Running setup.py install for itsdangerous ... done
Successfully installed Flask-0.11.1 Jinja2-2.8 MarkupSafe-0.23 Werkzeug-0.11.11
click-6.6 itsdangerous-0.24
The simple example of the running Flask python module is one script named hello.py:
from flask import Flask
app = Flask(__name__)

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

if __name__ == "__main__":
    app.run()
Using the command to run the script and show the result into your browser:
C:\Python27>python.exe hello.py
 * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
Now the installation of Flask-WTF python module:
C:\Python27\Scripts>pip install Flask-WTF
Collecting Flask-WTF
  Downloading Flask_WTF-0.14.2-py2.py3-none-any.whl
Collecting WTForms (from Flask-WTF)
  Downloading WTForms-2.1.zip (553kB)
    100% |################################| 563kB 1.7MB/s
Requirement already satisfied: Flask in c:\python27\lib\site-packages (from Flask-WTF)
Requirement already satisfied: click>=2.0 in c:\python27\lib\site-packages (from Flask->Flask-WTF)
Requirement already satisfied: Werkzeug>=0.7 in c:\python27\lib\site-packages (from Flask->Flask-WTF)
Requirement already satisfied: Jinja2>=2.4 in c:\python27\lib\site-packages (from Flask->Flask-WTF)
Requirement already satisfied: itsdangerous>=0.21 in c:\python27\lib\site-packages (from Flask->Flask-WTF)
Requirement already satisfied: MarkupSafe>=0.23 in c:\python27\lib\site-packages (from Jinja2>=2.4->Flask->Flask-WTF)
Installing collected packages: WTForms, Flask-WTF
  Running setup.py install for WTForms ... done
Successfully installed Flask-WTF-0.14.2 WTForms-2.1
Now I try with Python 3.6.2 with both python modules and works great.
C:\Python362\Scripts>pip3.6.exe install flask
...
Successfully installed Jinja2-2.9.6 MarkupSafe-1.0 Werkzeug-0.12.2 click-6.7 flask-0.12.2 itsdangerous-0.24

C:\Python362\Scripts>Flask-WTF
'Flask-WTF' is not recognized as an internal or external command,
operable program or batch file.

C:\Python362\Scripts>pip3.6.exe install Flask-WTF
...
Successfully installed Flask-WTF-0.14.2 WTForms-2.1

Thursday, December 1, 2016

Python 3.4 and Flask module - part 001.

This is a simple tutorial about how to install Flask python module under python 3.4 .
I think this can also working with any python 3.x versions.
Flask is a microframework for creating web applications.
First you need to install your python 3.4 and then you will get the pip script from here.
About pip you can read more on the pip webpage.
Run the pip install:
python get-pip.py

Go to into your Python folder and start the pip installation of Flask python module.
C:\Python34>cd Scripts
C:\Python34\Scripts>pip install Flask
Downloading/unpacking Flask

This is the first step. The next step is to start the default webpage.
Using python command shell you can test the Flask python module.

>>> from flask import Flask
>>>
>>> app = Flask(__name__)
>>>
>>> @app.route('/')
... def homepage():
... return "Hi there, how ya doin?"
...
>>>
>>> if __name__ == "__main__":
... app.run()
...
* Running on http://127.0.0.1:5000/
127.0.0.1 - - [26/Sep/2014 23:25:01] "GET / HTTP/1.1" 200 -
127.0.0.1 - - [26/Sep/2014 23:25:02] "GET /favicon.ico HTTP/1.1" 404 -


As you can see is running into browser at http://127.0.0.1:5000 .
Let's put this into one python script.
You need to make a new folder called FlaskApp and go to this folder.
Make a new script named app.py with the source code you tested.
Now you can just run the script and all will be working well.
Flask looks for template files inside the templates folder.
Go to the folder FlaskApp and create a folder called templates.
Now, create a file called index.html and fill with you html source code.
To call this index.html you need to add this line of source code ino your script:
from flask import Flask, render_template and
def main():
return render_template('index.html')

Start your python script and you will see the content of your index.html.