stackoverflow.com-q-45032233.py

thing = """1 ID:K-95 list of data

0 ID:D-56 list of other data"""

idtag = "K-95"

for line in thing.split('\n'):
    if line.startswith('1') and line.startswith(idtag, 5, 5+4):                                                                                            
        print(line)
    
# prints
# 1 ID:K-95 list of data