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>  

Python 3.7.4 : Create an Stand Alone Executable on Fedora distro.

In this tutorial I will show you how to create an Stand Alone Executable with Python version 3.7.4 and Fedora 30 distro.
First you need to install using the dnf tool the python3 package.
You can test it easy with this command:

[mythcat@desk dist]$ 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. 

I created a simple python script named test.py for testing:

import os
import sys
print("Hello!")

You need to install the pyinstaller python module.
Let's see this step with the output:

[mythcat@desk ~]$ pip3 install pyinstaller --user

Now you can use this python module to create Stand Alone Executable.

[mythcat@desk ~]$ pip3 install pyinstaller --user
Requirement already satisfied: pyinstaller in ./.local/lib/python3.7/site-packages (3.5)
Requirement already satisfied: setuptools in /usr/lib/python3.7/site-packages (from pyinstaller) (40.8.0)
Requirement already satisfied: altgraph in ./.local/lib/python3.7/site-packages (from pyinstaller) (0.16.1)
[mythcat@desk ~]$ pyinstaller --onefile test.py
561 INFO: PyInstaller: 3.5
561 INFO: Python: 3.7.4
571 INFO: Platform: Linux-5.2.9-200.fc30.x86_64-x86_64-with-fedora-30-Thirty
573 INFO: wrote /home/mythcat/test.spec
596 INFO: UPX is not available.
598 INFO: Extending PYTHONPATH with paths
['/home/mythcat', '/home/mythcat']
598 INFO: checking Analysis
624 INFO: Building because /home/mythcat/test.py changed
624 INFO: Initializing module dependency graph...
640 INFO: Initializing module graph hooks...
678 INFO: Analyzing base_library.zip ...
5247 INFO: running Analysis Analysis-00.toc
5352 INFO: Caching module hooks...
5376 INFO: Analyzing /home/mythcat/test.py
5396 INFO: Loading module hooks...
5397 INFO: Loading module hook "hook-xml.py"...
5775 INFO: Loading module hook "hook-pydoc.py"...
5800 INFO: Loading module hook "hook-encodings.py"...
5892 INFO: Looking for ctypes DLLs
5893 INFO: Analyzing run-time hooks ...
5901 INFO: Looking for dynamic libraries
6507 INFO: Looking for eggs
6507 INFO: Using Python library /lib64/libpython3.7m.so.1.0
6514 INFO: Warnings written to /home/mythcat/build/test/warn-test.txt
6547 INFO: Graph cross-reference written to /home/mythcat/build/test/xref-test.html
6604 INFO: checking PYZ
6607 INFO: Building because toc changed
6607 INFO: Building PYZ (ZlibArchive) /home/mythcat/build/test/PYZ-00.pyz
7030 INFO: Building PYZ (ZlibArchive) /home/mythcat/build/test/PYZ-00.pyz completed successfully.
7034 INFO: checking PKG
7035 INFO: Building because toc changed
7035 INFO: Building PKG (CArchive) PKG-00.pkg
10033 INFO: Building PKG (CArchive) PKG-00.pkg completed successfully.
10036 INFO: Bootloader 
/home/mythcat/.local/lib/python3.7/site-packages/PyInstaller/bootloader/Linux-64bit/run
10036 INFO: checking EXE
10123 INFO: Building because toc changed
10124 INFO: Building EXE from EXE-00.toc
10163 INFO: Appending archive to ELF section in EXE /home/mythcat/dist/test
10337 INFO: Building EXE from EXE-00.toc completed successfully.

This command will create some folders: dist, build, ...
The dist folder will have the Stand Alone Executable named test:

[mythcat@desk ~]$ cd dist/
[mythcat@desk dist]$ ls
test
[mythcat@desk dist]$ ./test
Hello!

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.

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.

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.