Valient's IT Notes

Getting UserAgent and Browser name in Flask, Python

Inspired by the book "Head First Python, 2nd Edition" by Paul Barry, released November 2016, Publisher(s): O'Reilly Media, Inc.
where some examples don't work
Pages 296-300 of that book

Task 4: Create Code to Work with Our Webapp’s Database and Tables

Determine the Flask version.
First way: two lines in IDLE


 import flask 
 print(flask.__version__)

Second way: one command in Command line:


 pip show flask

The installed Flask version is uptodate - 3.0.3

Determine the Python version.
First way: two lines in IDLE


 from platform import python_version 
 python_version()

Second way: one command in Command line again:


 python -V

The installed Python version is uptodate too - 3.12.3

Coding in Python, Flask


 from flask import Flask 
 from flask import render_template, request

The method request.user_agent.browser returns nothing.
The next method requires one more importing


 from ua_parser import user_agent_parser

These three lines returns the browser name in browser variable:


 web_detail = str(request.user_agent) 
 user_browser = user_agent_parser.ParseUserAgent(web_detail) 
 browser = user_browser['family']

or briefer in single code line


 user_agent_parser.Parse(request.user_agent.string)['user_agent']['family']

I digress a little from the main trend of this note and give a method that receives all the User Agent:


 request.headers.get("user-agent")

Summing up, I couldn't write it to the field "browser_string" in the table "log" of the database "vsearchlogDB" anything, the value after insert operation was Null

Unigui is not only uniGUI Web Application Framework for Delphi but Universal GUI Framework for Python

It turns out, the Unigui is not only uniGUI Web Application Framework for Delphi but Universal GUI Framework and Protocol for Python (on Github UNISI project)

How to Fix ImportError: cannot import name 'escape' from

ImportError: cannot import name 'escape' from 'flask'
or
ImportError: cannot import name 'escape' from 'jinja2'
There is no possibility to import name 'escape' from 'flask' (or jinja2).
Today the simplest way is to use from markupsafe import escape instead of from flask import escape.

Jinja is a dependency of Flask and Flask V1.X.X uses the escape module from Jinja, however support for the escape module was dropped in newer versions of Jinja.

Markup and escape should be imported from MarkupSafe.

from flask import escape was found on the page in the article It’s Time to Escape (Your Data) in the book "Head First Python, 2nd Edition" by Paul Barry, released November 2016, Publisher(s): O'Reilly Media, Inc.

Swapping two variables without using another variable (Arithmetic Operator)

a = 5 b = 10 a = a + b b = a - b a = a - b print(a, b) 10 5

I found this algorithm interesting.
Example made in Python

Three ways how to add a favicon in uniGui

A favicon (/ˈfæv.ɪˌkɒn/; short for favorite icon), also known as a shortcut icon, website icon, tab icon, URL icon, or bookmark icon, is a file containing one or more small icons associated with a particular website or web page.

In March 1999, Microsoft released Internet Explorer 5, which supported favicons for the first time. Originally, the favicon was a file called favicon.ico placed in the root directory of a website. It was used in Internet Explorer's favorites (bookmarks) and next to the URL in the address bar if the page was bookmarked.

Taken from Wikipedia

To add an icon to the site one must place an ico format file named favicon.ico in the root directory of the site.
But the uniGUI site does not have a root directory. Placing favicon.ico in the module directory does nothing.
This problem can be solved in various ways.

The Viber Analyzer on uniGui project and Embarcadero Delphi 10.4.1 Sydney are used as an example.

The first way is the most obvious.
Since web application is coded in Delphi, one can add an icon to it, like to an ordinary program.
The icon can be set in the Project->Options...->Application->Icons->Application Icon Settings->Icon.
And this icon will be the site icon.

Viber Analyzer on uniGui ScreenShot in Delphi

After compiling the project and refreshing the page in the browser, the icon is as needed.

The second way is a solution from the uniGUI.
A uniGui project has one specialized data module - TUniGUIServerModule.
This is a singleton object that implements server-side functions of a web application.
This module is in the forms list, one must select this module, find the "Favicon" property in the object inspector and load the icon into it.

Viber Analyzer on uniGui Server ScreenShot

UniGUI Server also changes its icon.
The UniGUI Server icon in the property of Windows application, which is visible, for example, in Windows Explorer, is taken from the Project Options in Delphi

The third way is one line of code in the OnBeforeInit event handler in the TUniGUIServerModule successor.
Now, on launching a web application, the icon will be loaded from an external file, and if missing, the icon can added by one of two ways previously described.

procedure TUniServerModule.UniGUIServerModuleBeforeInit(Sender: TObject);
begin
  try
    Favicon.LoadFromFile('favicon.ico');
  except
  end;
end;

procedure TUniServerModule.UniGUIServerModuleBeforeInit(Sender: TObject);
begin
  try
    TUniGUIServerModule(Sender).Favicon.LoadFromFile('favicon.ico');
  except
  end;
end;