var i:Integer;
    s:Char;
    str:string;
    F:File;
begin
   str:='';
   AssignFile(F,'1.txt');
   Reset(F,1);
   for i:=0 to FileSize(F)-1 do
   begin
      Seek(F,i);
      BlockRead(F,s,1);
      str:=str+s;
   end;
   CloseFile(F);
end;

Regex ptrn = new Regex("O[0-9]{5}");
string[] lst = ptrn.Split(CurrentProgs.fileContent);
foreach (var sub in lst)
{
    listBox1.Items.Add(sub);
}

import subprocess as sub
from tqdm import tqdm

process = sub.Popen("ffmpeg -i /240.mp4 -c:v libaom-av1 -pix_fmt yuv420p /output.mkv", shell=True, stdout=sub.PIPE, stderr=sub.PIPE, text=True)
with tqdm(total=100, desc="Processing", unit="%", ncols=100) as pbar:
    output = process.stdout.readline()
    error = process.stderr.readline()
    print(output)

Processing:   0%|                                                            | 0                        /100 [00:00<?, ?%/s]

            try
            {
                const string URL = "https://www.youtube.com/watch?v=fy0HRViXZnE";
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
                request.Method = "GET";
                request.Timeout = 5000;
                
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                int code = (int)response.StatusCode;
                Console.WriteLine($"OK: {code}");
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.HResult);
            }

            Console.ReadLine();

Exception thrown: 'System.Net.Sockets.SocketException' in System.dll
Exception thrown: 'System.IO.IOException' in System.dll
Exception thrown: 'System.IO.IOException' in System.dll
Exception thrown: 'System.IO.IOException' in System.dll
Exception thrown: 'System.IO.IOException' in System.dll
Exception thrown: 'System.IO.IOException' in System.dll
Exception thrown: 'System.ObjectDisposedException' in System.dll
Exception thrown: 'System.ObjectDisposedException' in System.dll
Exception thrown: 'System.ObjectDisposedException' in System.dll
Exception thrown: 'System.Net.WebException' in System.dll
Exception thrown: 'System.Net.WebException' in System.dll

procedure TForm1.Button1Click(Sender: TObject);
var s, s1: string;
    i: integer;
begin
   //s:='ABCabc АБВабвЁё';
   s:=Edit1.Text;
   Memo1.Clear;
   for i:=1 to Length(s) do
   begin
      s1:=Format('%s - %d - ', [s, Ord(s)]);
      if CharInSet(s, ['А'..'Я', 'а'..'я', 'Ё', 'ё']) then
      //if s in ['А'..'Я', 'а'..'я', 'Ё', 'ё'] then
         s1:=s1+'русская буква' else
         s1:=s1+'другой символ';
      Memo1.Lines.Add(s1);
   end;
end;

if s in ['А'..'Я', 'а'..'я', 'Ё', 'ё'] then