First line with digits before last line

[tester_V]

Thank you guys!
I appreciate your help!
I'm really not that good with programming.
I came up with a simple (for me) solution that seems working fine.
I probably invented a bicycle...

Here is the code:

import re
import linecache
 
fl = 'C:/01/last_line.txt'
with open(r"C:/01/last_line.txt") as mfiler:
    lnc = 0  # <-- Line Numners
    frt_ln = mfiler.readline()  # <------------------ First Line
    print(f" Fl -> {frt_ln}")
    
    for rn_l in mfiler:
        lnc+=1    
        if 'Start' in rn_l :
            continue        
            # do something with the lines
        la_line = rn_l
 
while (lnc) > 0 :
    print(f" Number of Ln in the File = {str(lnc)}") # < --- Number of lines in the file
    if re.search('^\d+', la_line) :
        print(f"  LN has DT --> {la_line} ")
        lnc = 0
        break
    else :
        lnc = lnc -1
        la_line = linecache.getline('C:/01/last_line.txt', lnc)

Thank you again!
I love this forum