Regex over multiple lines with \n - python-3.x

Question

In the following code I would like to capture the instance ID and then the body underneath it. The pattern is recurring so that there are multiple instances with the same bodies. I can't seem to figure out how to get it to continue past the newline segments.
import re
config = '''
Instance: evpn-a
VLAN ID: 123, MAC address: 00:05:86:71:05:f0
Source: irb.0, Rank: 1, Status: Active
State: <Local-MAC-Only Local-Gateway Remote-Adv-Allowed>
IP address: 192.168.10.251
VLAN ID: 123, MAC address: 00:05:86:71:ab:f0
Source: 20.1.1.2, Rank: 1, Status: Active
State: <Remote-Gateway Local-Adv-Allowed Local-Adv-Done>
IP address: 192.168.10.252
L3 route: 192.168.10.252/32, L3 context: bridge-vrf (irb.0)
Instance: evpn-b
VLAN ID: 123, MAC address: 00:05:86:71:05:f0
Source: irb.0, Rank: 1, Status: Active
State: <Local-MAC-Only Local-Gateway Remote-Adv-Allowed>
IP address: 192.168.10.251
VLAN ID: 123, MAC address: 00:05:86:71:ab:f0
Source: 20.1.1.2, Rank: 1, Status: Active
State: <Remote-Gateway Local-Adv-Allowed Local-Adv-Done>
IP address: 192.168.10.252
L3 route: 192.168.10.252/32, L3 context: bridge-vrf (irb.0)
'''
evpn_obj_list = re.compile(r'Instance:\s+(\S+)(.*?)(?:\S+|\Z)',re.S|re.M).findall(config)
evpn = evpn_obj_list
print(evpn)
The result I get from the above is:
[('evpn-a', '\n\n'), ('evpn-b', '\n\n')]

Answer 1

You may use
rx = re.compile(r'^Instance:\s+(\S+)\s*(.*?)(?=\n\s*Instance:\s|\Z)', re.S|re.M)
evpn_obj_list = rx.findall(config)
See the regex demo.
Details
^ - start of a line
Instance: - a string
\s+ - 1+ whitespaces
(\S+) - Group 1: any one or more non-whitespace chars
\s* - 0+ whitespaces
(.*?) - Group 2: any 0 or more chars, as few as possible
(?=\n\s*Instance:\s|\Z) - a positive lookahead that requires a newline, 0+ whitespaces, Instance:, a whitespace OR the end of file immediately to the right of the current location.
See the Python demo yielding
[('evpn-a', 'VLAN ID: 123, MAC address: 00:05:86:71:05:f0\n Source: irb.0, Rank: 1, Status: Active\n State: <Local-MAC-Only Local-Gateway Remote-Adv-Allowed>\n IP address: 192.168.10.251\n\nVLAN ID: 123, MAC address: 00:05:86:71:ab:f0\n Source: 20.1.1.2, Rank: 1, Status: Active\n State: <Remote-Gateway Local-Adv-Allowed Local-Adv-Done>\n IP address: 192.168.10.252\n L3 route: 192.168.10.252/32, L3 context: bridge-vrf (irb.0)'), ('evpn-b', 'VLAN ID: 123, MAC address: 00:05:86:71:05:f0\n Source: irb.0, Rank: 1, Status: Active\n State: <Local-MAC-Only Local-Gateway Remote-Adv-Allowed>\n IP address: 192.168.10.251\n\nVLAN ID: 123, MAC address: 00:05:86:71:ab:f0\n Source: 20.1.1.2, Rank: 1, Status: Active\n State: <Remote-Gateway Local-Adv-Allowed Local-Adv-Done>\n IP address: 192.168.10.252\n L3 route: 192.168.10.252/32, L3 context: bridge-vrf (irb.0)\n')]