Regular Expressions: players challenge task 1 of 2

This is the task with the string:

string = '''Love, Kenneth: 20
Chalkley, Andrew: 25
McFarland, Dave: 10
Kesten, Joy: 22
Stewart Pinchback, Pinckney Benton: 18'''

I need to match three groups with re.search: last_name, first_name, and score. I was able to complete the challenge, but I have a lingering question.

The first time I wrote my RE pattern, I used the set [a-zA-Z]+ to capture the last name. Of course, the lack of white space in the set will fail to catch the last last name in the string. That's obvious, but what I was surprised about was the fact that the code checker caught this mistake. I was expecting the re.search to only catch the first match: "Love, Kenneth: 20". When I run this code in Python, I get

>>> players
<_sre.SRE_Match object; span=(0, 17), match='Love, Kenneth: 20'>

Can you help me understand this? Is the code checker running a loop on all lines?

import re

string = '''Love, Kenneth: 20
Chalkley, Andrew: 25
McFarland, Dave: 10
Kesten, Joy: 22
Stewart Pinchback, Pinckney Benton: 18'''

[MOD: added ```python formatting -cf]