Welcome to django_ocr_server’s documentation!

Introduction

Django-ocr-server lets you recognize images and PDF. It is using tesseract for this. https://github.com/tesseract-ocr/tesseract

Django-ocr-server saves the result in the database. To prevent repeated recognition of the same file, it also saves the hash sum of the uploaded file. Therefore, when reloading an already existing file, the result returns immediately, bypassing the recognition process, which significantly reduces the load on the server.

If as a result of recognition a non-empty text is received, a searchable PDF is created.

For the searchable PDF is calculated hash sum too. Therefore, if you upload the created by Django-ocr-server searchable pdf to the server back, then this file will not be recognized, but the result will be immediately returned.

The server can process not only images, but PDF. At the same time, he analyzes, if the PDF already contains real text, this text will be used and the file will not be recognized, which reduces the load on the server and improves the quality of the output.

Storage of downloaded files and created searchable PDFs can be disabled in the settings.

For uploaded files and created searchable PDFs, and the processing results whole in the settings you can specify the lifetime after which the data will be automatically deleted.

To interact with Django-ocr-server you can use API or the admin interface.

Installation

Linux Mint 19 (Ubuntu bionic)

Installing packages

$ sudo apt install g++  # need to build pdftotext
$ sudo apt install libpoppler-cpp-dev  # need to buid pdftotext

Installing tesseract

$ sudo apt install tesseract-ocr
$ sudo apt install tesseract-ocr-rus  # install languages you want

Installing ghostscript

$ sudo apt install ghostscript

Installing python3.7

$ sudo apt install python3.7
$ sudo apt install python3.7-dev

Installing pip

$ sudo apt install python-pip

Installing virtualenv

$ pip install --user virtualenv
$ echo 'PATH=~/.local/bin:$PATH' >> ~/.bashrc
$ source ~/.bashrc

Installing virtualenvwrapper

$ pip install --user setuptools
$ pip install --user wheel
$ pip install --user virtualenvwrapper
$ echo 'source ~/.local/bin/virtualenvwrapper.sh' >> ~/.bashrc
$ source ~/.bashrc

Creating virtualenv for django_ocr_server

$ mkvirtualenv django_ocr_server -p /usr/bin/python3.7

Installing django-ocr-server (on virtualenv django_ocr_server). It installs Django as a dependency.

$ pip install django-ocr-server

Create your Django project (on virtualenv django_ocr_server)

$ django-admin startproject ocr_server

Go to project directory

$ cd ocr_server

Edit ocr_server/settings.py

Add applications to INSTALLED_APPS

INSTALLED_APPS = [
    ...
    'rest_framework',
    'rest_framework.authtoken',
    'django_ocr_server',
    'rest_framework_swagger',
]

Edit ocr_server/urls.py

from django.contrib import admin
from django.urls import path, include
from rest_framework.documentation import include_docs_urls

admin.site.site_header = 'OCR Server Administration'
admin.site.site_title = 'Welcome to OCR Server Administration Portal'

urlpatterns = [
    path('admin/', admin.site.urls, ),
    path('docs/', include_docs_urls(title='OCR Server API')),
    path('', include('django_ocr_server.urls'), ),
]

Perform migrations (on virtualenv django_ocr_server)

$ python manage.py migrate

Create superuser (on virtualenv django_ocr_server)

$ python manage.py createsuperuser

Run server (on virtualenv django_ocr_server), than visit http://localhost:8000/

$ python manage.py runserver

Linux Mint 19 (Ubuntu bionic) automatic installation

Clone django_ocr_server from github

$ git clone https://github.com/shmakovpn/django_ocr_server.git

Run the installation script using sudo

$sudo {your_path}/django_ocr_server/install_ubuntu.sh

The script creates OS user named ‘django_ocr_server’, installs all needed packages. Creates the virtual environment. It installs django_ocr_server (from PyPI by default, but you can create the package from cloned repository, see the topic ‘Creation a distribution package’ how to do this). Then it creates the django project named ‘ocr_server’ in the home directory of ‘django_ocr_server’ OS user. After the script changes settings.py and urls.py is placed in ~django_ocr_server/ocr_server/ocr_server/. Finally it applies migrations and creates the superuser named ‘admin’ with the same password ‘admin’.

Run server under OS user django_ocr_server, then change ‘admin’ password in the http://localhost:your_port/admin/ page.

$ sudo su
# su django_ocr_server
$ cd ~/ocr_server
$ workon django_ocr_server
$ python manage.py runserver

Centos 7

Install epel repository

$ sudo yum install epel-release

Install yum-utils

$ sudo yum install yum-utils

Install ghostscript (Interpreter for PostScript language & PDF needed for ocrmypdf)

$ sudo yum install ghostscript

Install wget (A utility for retrieving files using the HTTP or FTP protocols for download qpdf that needed for ocrmypdf)

$ sudo yum install wget

Install qpdf

$ cd /usr/local/src
$ wget https://github.com/qpdf/qpdf/releases/download/release-qpdf-9.1.0/qpdf-9.1.0.tar.gz
$ # TODO tar -zxvf qpdf-9.1.0.tar.gz
$ # TODO cd qpdf-9.1.0
$ # TODO ./Configure
$ # TODO make
$ # TODO make install

Install python 3.6

$ sudo yum install python36
$ sudo yum install python36-devel

Install gcc

$ sudo yum intall gcc
$ sudo yum install gcc-c++

Install poppler-cpp-devel (Development files for C++ wrapper for building pdftotext)

$ sudo yum install poppler-cpp-devel

Install tesseract

$ sudo yum-config-manager --add-repo https://download.opensuse.org/repositories/home:/Alexander_Pozdnyakov/CentOS_7/
$ sudo bash -c "echo 'gpgcheck=0' >> /etc/yum.repos.d/download.opensuse.org_repositories_home_Alexander_Pozdnyakov_CentOS_7*.repo"
$ sudo yum update
$ sudo yum install tesseract
$ sudo yum install tesseract-langpack-rus  # install a language pack you need

Install pip

$ sudo yum install python-pip

Install virtualenv

$ sudo pip install virtualenv

Create the virtual env for django_ocr_server

$ sudo virtualenv /var/www/ocr_server/venv -p /usr/bin/python3.6 --distribute

Give rights to the project folder to your user

$ sudo chown -R {your_user} /var/www/ocr_server/

Activate virtualenv

$ source /var/www/ocr_server/venv/bin/activate

Install postgresql 11 (The Postgresql version 9.2 that is installing in Centos 7 by default returns an error when applying migrations )

$ sudo rpm -Uvh https://yum.postgresql.org/11/redhat/rhel-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm
$ sudo yum install postgresql11-server
$ sudo yum install postgresql-devel
$ sudo /usr/pgsql-11/bin/postgresql-11-setup initdb

Edit /var/lib/pgsql/11/data/pg_hba.conf

host    all             all             127.0.0.1/32            md5
host    all             all             ::1/128                 md5

$ sudo systemctl enable postgresql-11
$ sudo systemctl start postgresql-11
$ sudo -u postgres psql

Create the database and it’s user

create database django_ocr_server encoding utf8;
create user django_ocr_server with password 'django_ocr_server';
alter database django_ocr_server owner to django_ocr_server;
alter user django_ocr_server createdb;  -- if you want to run tests
\q

Install python postgres database driver

$ pip install psycopg2-binary  # (on virtualenv django_ocr_server)

Installing django-ocr-server (on virtualenv django_ocr_server). It installs Django as a dependency

$ pip install django-ocr-server

Create django project (on virtualenv django_ocr_server)

$ cd /var/www/ocr_server
$ django-admin startproject ocr_server .

Edit ocr_server/settings.py

Add applications to INSTALLED_APPS

INSTALLED_APPS = [
    ...
    'rest_framework',
    'rest_framework.authtoken',
    'django_ocr_server',
    'rest_framework_swagger',
]

Configure database connection

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'django_ocr_server',
        'USER': 'django_ocr_server',
        'PASSWORD': 'django_ocr_server',
        'HOST': 'localhost',
        'PORT': '',
    }
}

Edit ocr_server/urls.py

from django.contrib import admin
from django.urls import path, include
from rest_framework.documentation import include_docs_urls

admin.site.site_header = 'OCR Server Administration'
admin.site.site_title = 'Welcome to OCR Server Administration Portal'

urlpatterns = [
    path('admin/', admin.site.urls, ),
    path('docs/', include_docs_urls(title='OCR Server API')),
    path('', include('django_ocr_server.urls'), ),
]

Apply migrations (on virtualenv django_ocr_server)

$ python manage.py migrate

Create superuser (on virtualenv django_ocr_server)

$ python manage.py createsuperuser

Run server (on virtualenv django_ocr_server), than visit http://localhost:8000/

$ python manage.py runserver

Configuration

For changing your django_ocr_server behavior you can use several parameters in the settings.py of your django project.

django_ocr_server.default_settings.OCR_STORE_FILES = True

Store uploaded files (True) or not (False), default to True

django_ocr_server.default_settings.OCR_FILE_PREVIEW = True

Show file preview in admin (True) or not (False), default to True

django_ocr_server.default_settings.OCR_TESSERACT_LANG = 'rus+eng'

Sets priority of using languages, default to ‘rus+eng’

django_ocr_server.default_settings.OCR_STORE_PDF = True

Generate and store recognized searchable PDF (True) or not (False), default to True

django_ocr_server.default_settings.OCR_STORE_FILES_DISABLED_LABEL = 'store_files_disabled'

The text of storeing uploaded files disabled label in the admin interface

django_ocr_server.default_settings.OCR_STORE_PDF_DISABLED_LABEL = 'store_pdf_disabled'

The text of storeing recognized PDF disabled label in the admin interface

django_ocr_server.default_settings.OCR_FILE_REMOVED_LABEL = 'file_removed'

The text of the label of file removed in the admin interface

django_ocr_server.default_settings.OCR_PDF_REMOVED_LABEL = 'pdf_removed'

The text of the label of PDF removed in the admin interface

django_ocr_server.default_settings.OCR_ALLOWED_FILE_TYPES = ['application/pdf', 'image/jpeg', 'image/png', 'image/bmp', 'image/tiff']

The types of file allowed to uploading

django_ocr_server.default_settings.OCR_FILES_UPLOAD_TO = '/home/docs/checkouts/readthedocs.org/user_builds/django-ocr-server/checkouts/latest/django_ocr_server/upload'

The directory for saving uploaded files

django_ocr_server.default_settings.OCR_PDF_UPLOAD_TO = '/home/docs/checkouts/readthedocs.org/user_builds/django-ocr-server/checkouts/latest/django_ocr_server/pdf'

The directory for storeing searchable PDFs

Time to live settings

django_ocr_server.default_settings.OCR_FILES_TTL = datetime.timedelta(0)

When current datetime will be grater then the datetime of file uploading plus this timedelta, the uploaded file will be removed. timedelta(0) means that OCR_FILES_TTL is disabled. Defaults to timedelta(0).

django_ocr_server.default_settings.OCR_PDF_TTL = datetime.timedelta(0)

When current datetime will be grater then the datetime of creating recognized PDF plus this timedelta, the recognized PDF will be removed. timedelta(0) means that OCR_PDF_TTL is disabled. Defaults to timedelta(0).

django_ocr_server.default_settings.OCR_TTL = datetime.timedelta(0)

When current datetime will be grater then the datetime of creating the model (OCRedFile) in the database plus this timedelta, the model in the database will be removed. timedelta(0) means that OCR_TTL is disabled. Defaults to timedelta(0).

Deploying to production

Linux Mint 19 (Ubuntu bionic)

Installing nginx

$ sudo apt install nginx

Installing uwsgi (on virtualenv django_ocr_server)

$ pip install uwsgi

Create {path_to_your_project}/uwsgi.ini

[uwsgi]
  chdir = {path_to_your_project}  # e.g. /home/shmakovpn/ocr_server
  module = {your_project}.wsgi  # e.g. ocr_server.wsgi
  home = {path_to_your_virtualenv}  # e.g. /home/shmakovpn/.virtualenvs/django_ocr_server
  master = true
  processes = 10
  http = 127.0.0.1:8003
  vacuum = true

Create /etc/nginx/sites-available/django_ocr_server.conf

server {
    listen 80;  # choose port what you want
    server_name _;
    charset utf-8;
    client_max_body_size 75M;
    location /static/rest_framework_swagger {
        alias {path_to_your virtualenv}/lib/python3.6/site-packages/rest_framework_swagger/static/rest_framework_swagger;
    }
    location /static/rest_framework {
        alias {path_to_your virtualenv}/lib/python3.7/site-packages/rest_framework/static/rest_framework;
    }
    location /static/admin {
        alias {path_to_your virtualenv}/lib/python3.7/site-packages/django/contrib/admin/static/admin;
    }
    location / {
        proxy_pass http://127.0.0.1:8003;
    }
}

Enable the django_ocr_server site

$ sudo ln -s /etc/nginx/sites-available/django_ocr_server.conf /etc/nginx/sites-enabled/

Remove the nginx default site

$ sudo rm /etc/nginx/sites-enabled/default

Create the systemd service unit /etc/systemd/system/django-ocr-server.service

[Unit]
  Description=uWSGI Django OCR Server
  After=syslog.service

[Service]
  User={your user}
  Group={your group}
  Environment="PATH={path_to_your_virtualenv}/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
  ExecStart={path_to_your_virtualenv}/bin/uwsgi --ini {path_to_your_project}/uwsgi.ini
  RuntimeDirectory=uwsgi
  Restart=always
  KillSignal=SIGQUIT
  Type=notify
  StandardError=syslog
  NotifyAccess=all

[Install]
  WantedBy=multi-user.target

Reload systemd

$ sudo systemctl daemon-reload

Start the django-ocr-server service

$ sudo systemctl start django-ocr-server

Enable the django-ocr-server service to start automatically after server is booted

$ sudo systemclt enable django-ocr-server

Start nginx

$ sudo systemctl start nginx

Enable nginx service to start automatically after server is booted

$ sudo systemctl enable nginx

Go to http://{your_server}:80 You will be redirected to admin page

Centos 7

Installing nginx

$ sudo apt install nginx

Installing uwsgi (on virtualenv django_ocr_server)

$ pip install uwsgi

Create /var/www/ocr_server/uwsgi.ini

[uwsgi]
  chdir = /var/www/ocr_server
  module = ocr_server.wsgi
  home = /var/www/ocr_server/venv
  master = true
  processes = 10
  http = 127.0.0.1:8003
  vacuum = true

Create the systemd service unit /etc/systemd/system/django-ocr-server.service

[Unit]
  Description=uWSGI Django OCR Server
  After=syslog.service

[Service]
  User=nginx
  Group=nginx
  Environment="PATH=/var/www/ocr_server/venv/bin:/sbin:/bin:/usr/sbin:/usr/bin"
  ExecStart=/var/www/ocr_server/venv/bin/uwsgi --ini /var/www/ocr_server/uwsgi.ini
  RuntimeDirectory=uwsgi
  Restart=always
  KillSignal=SIGQUIT
  Type=notify
  StandardError=syslog
  NotifyAccess=all

[Install]
  WantedBy=multi-user.target

Reload systemd service

$ sudo systemctl daemon-reload

Chango user of /var/www/ocr_server to nginx

$ sudo chown -R nginx:nginx /var/www/ocr_server

Start Django-ocr-server service

$ sudo systemctl start django-ocr-service

Check that port is up

$ sudo netstat -anlpt \| grep 8003

you have to got something like this:

tcp        0      0 127.0.0.1:8003          0.0.0.0:*               LISTEN      2825/uwsgi

Enable Django-ocr-server uwsgi service

$ sudo systemctl enable django-ocr-service

Edit /etc/nginx/nginx.conf

server {
    listen       80 default_server;
    listen       [::]:80 default_server;
    server_name  _;
    charset utf-8;
    client_max_body_size 75M;
    location /static/rest_framework_swagger {
        alias /var/www/ocr_server/venv/lib/python3.6/site-packages/rest_framework_swagger/static/rest_framework_swagger;
    }
    location /static/rest_framework {
        alias /var/www/ocr_server/venv/lib/python3.6/site-packages/rest_framework/static/rest_framework;
    }
    location /static/admin {
        alias /var/www/ocr_server/venv/lib/python3.6/site-packages/django/contrib/admin/static/admin;
    }
    location / {
        proxy_pass http://127.0.0.1:8003;
    }
}

Configure SELinux

Django has a bug (https://code.djangoproject.com/ticket/29027#no1)

By default it stores uploading files size more than 2,5Mb to /tmp folder. A temp file gets ‘system_u:object_r:httpd_tmp_t:s0’ SELinux context. Then Django tries to copy this file to the uploading folder with its SELinux context using os.setxattr() from lib/python3.6/shutil.py. But it is a wrong behavior because in the uploading folder the SELinux context of a file have to be ‘http_sys_rw_content_t’. To solve the problem we have to create another folder for temp files with ‘http_sys_rw_content_t’ for example /var/www/ocr_server/tmp. Then configure Django to store temp files to this folder.

$ sudo mkdir /var/www/ocr_server/tmp
$ sudo chown {your_user} /var/www/ocr_server/tmp

Change /var/www/ocr_server/ocr_server/settings.py

FILE_UPLOAD_TEMP_DIR = os.path.join(BASE_DIR, 'tmp')

Configure SELinux contexts

$ sudo semanage port -a -t http_port_t -p tcp 8003
$ sudo semanage fcontext -a -t httpd_sys_content_t '/var/www/ocr_server/venv/lib/python3.6/site-packages/rest_framework_swagger/static/rest_framework_swagger(/.*)?'
$ sudo semanage fcontext -a -t httpd_sys_content_t '/var/www/ocr_server/venv/lib/python3.6/site-packages/rest_framework/static/rest_framework(/.*)?'
$ sudo semanage fcontext -a -t httpd_sys_content_t '/var/www/ocr_server/venv/lib/python3.6/site-packages/django/contrib/admin/static/admin(/.*)?'
$ find /var/www/ocr_server/venv/lib/python3.6/site-packages/ | grep '\.so' | grep -v '\.libs' | xargs -L1 sudo semanage fcontext -a -t httpd_sys_script_exec_t
$ sudo semanage fcontext -a -t httpd_sys_script_exec_t '/var/www/ocr_server/venv/bin(/.*)?'
$ sudo semanage fcontext -a -t httpd_sys_script_exec_t '/var/www/ocr_server/venv/lib/python3.6/site-packages/psycopg2/.libs(/.*)?'
$ sudo semanage fcontext -a -t httpd_sys_rw_content_t '/var/www/ocr_server/django_ocr_server/upload(/.*)?'
$ sudo semanage fcontext -a -t httpd_sys_rw_content_t '/var/www/ocr_server/django_ocr_server/pdf(/.*)?'
$ sudo semanage fcontext -a -t httpd_sys_rw_content_t '/var/www/ocr_server/tmp(./*)?'
$ sudo restorecon -Rv /var/www/ocr_server
$ sudo setsebool -P httpd_can_network_connect_db 1

Start nginx service

$ sudo systemctl start nginx

Enable nginx service

$ sudo systemctl enable nginx

Configure firewall

$ sudo firewall-cmd --zone=public --add-service=http --permanent
$ sudo firewall-cmd --reload

Go to http://{your_server}:80

You will be redirected to admin page

Usage examples

You can download all examples from https://github.com/shmakovpn/django_ocr_server/tree/master/usage_examples

curl

Use curl with ‘@’ before the path of the uploading file

#!/usr/bin/env bash
curl -F "file=@example.png" localhost:8000/upload/

python

Use requests.post function

import requests


with open("example.png", 'rb') as fp:
    print(requests.post("http://localhost:8000/upload/",
                        files={'file': fp}, ).content)

perl

Use LWP::UserAgent and HTTP::Request::Common

#!/usr/bin/perl
use strict;
use warnings FATAL => 'all';
use LWP::UserAgent;
use HTTP::Request::Common;

my $ua = LWP::UserAgent->new;
my $url = "http://localhost:8000/upload/";
my $fname = "example.png";

my $req = POST($url,
    Content_Type => 'form-data',
    Content => [
        file => [ $fname ]
    ]);

my $response = $ua->request($req);

if ($response->is_success()) {
    print "OK: ", $response->content;
} else {
    print "Failed: ", $response->as_string;
}

php

Use CURLFile($file, $mime, $name)

<?php
//Initialise the cURL var
$ch = curl_init();

//Get the response from cURL
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

//Set the Url
curl_setopt($ch, CURLOPT_URL, 'http://localhost:8000/upload/');

//Create a POST array with the file in it
$file='example.png';
$mime=getimagesize($file)['mime'];
$name=pathinfo($file)['basename'];
$postData = array(
    'file' => new CURLFile($file, $mime, $name),
);

curl_setopt($ch, CURLOPT_POSTFIELDS, $postData);

// Execute the request
$response = curl_exec(  $ch);
echo($response);

curl_close ($ch);

?>

Running tests

Perform under you django_ocr_server virtual environment

$python manage.py test django_ocr_server.tests

API documentation

Django-ocr-server provides API documentation use restframework.documentation and swagger.

Visit http://localhost:8000/swagger and http://localhost:8000/docs/

Management Commands

Run it to clean trash. It removes all uploaded files and PDFs that do not have related models in database.

$ python manage.py clean

Run it to remove models, uploaded files and PDFs, whose time to live (TTL) has expired.

$ python manage.py ttl

Create the user for API (return the AUTH-token).

$ python manage.py create_user username password
b2db7002e037a4edb25aed33b04b97e468970376

Creation a distribution package

As mentioned earlier, the automatic installation script ‘install_ubuntu.sh’ uses the package from the PyPI repository by default. To change this behavior or if you need your own distribution package you can build it.

Run command

$cd path to cloned project from github

$python setup.py sdist

Look in ‘dist’ directory, there is your package was created.

Also you can continue automatic installation. The package will be used.

Developer Guide

django_ocr_server/default_settings.py

The default settings of django_ocr_server.

"""
django_ocr_server/default_settings.py
+++++++++++++++++++++++++++++++++++++

This file contains default settings for OCR Server

| Author: shmakovpn <shmakovpn@yandex.ru>
| Date: 2019-02-21/2019-03-29/2019-04-12/2021-01-19
"""
from typing import List
import os
from datetime import timedelta
from django.conf import settings

# configure Django's settings if not configured (need for Sphinx autodoc)
if not settings.configured:
    settings.configure(
        BASE_DIR=os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

OCR_STORE_FILES: bool = True  #: Store uploaded files (True) or not (False), default to True
OCR_FILE_PREVIEW: bool = True  #: Show file preview in admin (True) or not (False), default to True
OCR_TESSERACT_LANG: str = 'rus+eng'  #: Sets priority of using languages, default to 'rus+eng'
OCR_STORE_PDF: bool = True  #: Generate and store recognized searchable PDF (True) or not (False), default to True

OCR_STORE_FILES_DISABLED_LABEL: str = 'store_files_disabled'
"""The text of storeing uploaded files disabled label in the admin interface"""

OCR_STORE_PDF_DISABLED_LABEL: str = 'store_pdf_disabled'
"""The text of storeing recognized PDF disabled label in the admin interface"""

OCR_FILE_REMOVED_LABEL: str = 'file_removed'
"""The text of the label of *file removed* in the admin interface"""

OCR_PDF_REMOVED_LABEL: str = 'pdf_removed'
"""The text of the label of *PDF removed* in the admin interface"""

OCR_ALLOWED_FILE_TYPES: List[str] = [
    'application/pdf',
    'image/jpeg',
    'image/png',
    'image/bmp',
    'image/tiff',
]
"""The types of file allowed to uploading"""
"""
2019-10-22 shmakovpn. An error was found when trying to deploy Django-OCR_Server using Apache
because usage of relative paths is a wrong way when Apache mod_wsgi is using
https://modwsgi.readthedocs.io/en/develop/user-guides/application-issues.html#application-working-directory
"""

OCR_FILES_UPLOAD_TO: str = os.path.join(settings.BASE_DIR, __package__,
                                        'upload')
"""The directory for saving uploaded files"""

OCR_PDF_UPLOAD_TO: str = os.path.join(settings.BASE_DIR, __package__, 'pdf')
"""The directory for storeing searchable PDFs"""

OCR_FILES_TTL: timedelta = timedelta(0)
"""
When current datetime will be grater then the datetime of file uploading plus this timedelta,
the uploaded file will be removed.
*timedelta(0)* means that **OCR_FILES_TTL** is disabled.
Defaults to *timedelta(0)*.
"""

OCR_PDF_TTL: timedelta = timedelta(0)
"""
When current datetime will be grater then the datetime of creating recognized PDF plus this timedelta,
the recognized PDF will be removed.
*timedelta(0)* means that **OCR_PDF_TTL** is disabled.
Defaults to *timedelta(0)*.
"""

OCR_TTL: timedelta = timedelta(0)
"""
When current datetime will be grater then the datetime of creating the model (OCRedFile) in the database plus this timedelta,
the model in the database will be removed.
*timedelta(0)* means that **OCR_TTL** is disabled.
Defaults to *timedelta(0)*.
"""

django_ocr_server/conf.py

The settings manager of django_ocr_server.

django_ocr_server/conf.py

The settings manager for django_ocr_server.

Usage:

from django_ocr_server.conf import ocr_settings
# Next line will print a value of **OCR_TESSERACT_LANG**
# using the variable from the Django's *settings.py* file
# if the variable is set there.
# Or the default value of **OCR_TESSERACT_LANG** from
# *django_ocr_server/default_settings.py* otherwise.
print(ocr_settings.OCR_TESSERACT_LANG)

Author: shmakovpn <shmakovpn@yandex.ru>

Date: 2021-01-20

class django_ocr_server.conf.DjangoOcrSettings

The settings manager of django_ocr_server

django_ocr_server.conf.ocr_settings = <django_ocr_server.conf.DjangoOcrSettings object>

The instance of settings manager of django_ocr_server

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