How to extract specific and delimited parts in .tex file for Flashcards?

Here, I introduce the QandA environment to accomplish the task.

This environment will output its contents into the document as part of a subsection named Questions and Answers. It will also use a modified version of protected@iwrite to output the subsection header as well as the environment contents to a file, in this case called userdata.tex.

documentclass[10pt]{article} 
usepackage{xpatch, environ}
makeatletter
% get a copy of `protected@write
letprotected@iwriteprotected@write
% patch the copy to add immediate
xpatchcmd{protected@iwrite}{write}{immediatewrite}{}{}

NewEnviron{QandA}{subsection{Questions and Answers}BODY%
  protected@iwritetempfile{letsubsectionrelax}%
    {subsection{Questions and Answers}}
  protected@iwritetempfile{letrelax}{BODY}}
makeatother

newwritetempfile

title{Italy} 
author{ahmedfarrag17} 
begin{document} 
immediateopenouttempfile=userdata.tex
section{Introduction}

Italy is a country consisting of a peninsula delimited by the Alps and
several islands surrounding it. Italy is located in the center of the
Mediterranean Sea, in Southern Europe, and is also often considered
part of Western Europe. A unitary parliamentary republic with Rome as
its capital and largest city, the country covers a total area of
301,340 km2.

begin{QandA}%
Where is Italy located?
Italy is located in the center of the
Mediterranean Sea, in Southern Europe.

What is the capital of Italy?
Rome.
end{QandA}

section{Borders and Population} 

Italy shares land borders with France, Switzerland, Austria and
Slovenia. Its population is about 60 million people.

begin{QandA}
Which countries share a border with Italy?
France, Switzerland, Austria and Slovenia.
end{QandA}

immediatecloseouttempfile
end{document}

the contents of userdata.tex are:

subsection {Questions and Answers}
Where is Italy located? Italy is located in the center of the Mediterranean Sea, in Southern Europe. par What is the capital of Italy? Rome.
subsection {Questions and Answers}
Which countries share a border with Italy? France, Switzerland, Austria and Slovenia.

The patched version of protected@iwrite I got from egreg's answer at Writing to a File