First line with digits before last line

[deanhystad]

import io
import re

data = io.StringIO("""
This is not the first line
2022-08-14 14:37:46.523,17784 ,Information,"==================== Bac Start Run ===================="
2022-08-14 14:37:46.523,17784 ,Information,"Bac Info:
[DS_DK] Bac Test Result : Passed
[DS_DK] Bac Iteration Result : Passed
2022-08-14 14:37:46.524,17784 ,Warning
Condition: NO Condition
Allowed Stages: Any Stage
Set Type: Hard
2022-08-14 14:39:00.032,15060 ,Information, Available network interfaces :
[Bac Setup] Ethernet Connection -2
[Bac Setup] USB 3.0 to GB Ethernet
""")

date_pattern = re.compile("^\d{4}-\d{2}-\d{2}")

first = last = None
for line in data:
    if re.search(date_pattern, line):
        last = line
        if first is None:
            first = line

print(first)
print(last)

Output:
2022-08-14 14:37:46.523,17784 ,Information,"==================== Bac Start Run ===================="

2022-08-14 14:39:00.032,15060 ,Information, Available network interfaces :