Create loops in loops by own commands using recursion

Question

I'm struggling a little with recursion. I have a .txt file with commands like this (< are comments):

< HEADER 1
< HEADER 2
DO STH HERE
LOOP lblA 2
DO STH 
DO STH ELSE
END  lblA
DO STH HERE

If there is a "LOOP lbl x" command, the tool have to repeat every command between this line and the "END lbl" x times. The output is saved temporarily before sending each line via TCP to a server:

< HEADER 1
< HEADER 2
DO STH HERE
< LOOP lblA 1 of 2
DO STH
DO STH ELSE
< LOOP lblA 2 of 2
DO STH
DO STH ELSE
< END LOOP lblA
DO STH HERE

That is easy. But now I want loops in loops like

< HEADER 1
< HEADER 2
DO STH HERE
LOOP lblA 2
DO STH
LOOP lblB 3
print("nope")
END lblB 3
DO STH ELSE
END  lblA
DO STH HERE

The output must be

< HEADER 1
< HEADER 2
DO STH HERE
< LOOP lblA 1 of 2
DO STH
< LOOP lblB 1 of 3
print("nope")
< LOOP lblB 2 of 3
print("nope")
< LOOP lblB 3 of 3
print("nope")
< END LOOP lblB
DO STH ELSE
< LOOP lblA 2 of 2
DO STH
< LOOP lblB 1 of 3
print("nope")
< LOOP lblB 2 of 3
print("nope")
< LOOP lblB 3 of 3
print("nope")
< END LOOP lblB
DO STH ELSE
< END LOOP lblA
DO STH HERE

This is my code so far:

def comTester(self, testfile):
    rawtext = Path(testfile).read_text()
    txt = rawtext.split('\n')
    for i in range (0, len(txt), 1):
       loopArray = []
       loopLineA = 0
       loopLineB = 0
       loopLbl = ''
       loops = 0
       j = 0
       k = 1
       if txt[i].startswith('<') == True:
          testcommands.append(txt[i])
       elif txt[i].startswith('LOOP') == True:
          loopArray = txt[i].split(' ')
          loopLineA = i + 1
          loopLbl = loopArray[1]
          loops = int(loopArray[2])
          for j in range (loopLineA, len(txt), 1):
             if txt[j].startswith('END ' + loopLbl) == True:
                loopLineB = j
          while k < loops:
             l = 0
             testcommands.append('< LOOP "' + loopLbl + str(k) + ' of ' + str(loops))
             for l in range(loopLineA, loopLineB, 1):
                testcommands.append(txt[l])
             k = k + 1
          testcommands.append('# END LOOP ' + loopLbl)
       elif txt[i].startswith('END') == True:
          continue
       else:
          testcommands.append(txt[i])
return

I need to start the "elif txt[i].startswith('LOOP') == True:" block recursive, but I don't know how. I have to create a new function and calling it itself. But with this given structure... no clue.