import re
s='''1.29.7D59 ; This field should not be edited
SE5C620.86B.00.01 ; This field should not be edited
I/O Sensitive ;Options: Balanced=00: I/O Sensitive=02
POR - Reg. Value:0x1F ;Options: 0.0%=00: 0.1%=01'''
lines = s.split('\n')
res = []
for line in lines:
res.append(re.split(r'\s*;', line)[0])
print(res)
aW1wb3J0IHJlCnM9JycnMS4yOS43RDU5ICAgICAgICAgICAgICAgICAgICAgICA7IFRoaXMgZmllbGQgc2hvdWxkIG5vdCBiZSBlZGl0ZWQKU0U1QzYyMC44NkIuMDAuMDEgICA7IFRoaXMgZmllbGQgc2hvdWxkIG5vdCBiZSBlZGl0ZWQKSS9PIFNlbnNpdGl2ZSAgICAgICAgICAgICAgIDtPcHRpb25zOiBCYWxhbmNlZD0wMDogSS9PIFNlbnNpdGl2ZT0wMgpQT1IgLSBSZWcuIFZhbHVlOjB4MUYgICAgICAgICAgICAgICAgIDtPcHRpb25zOiAwLjAlPTAwOiAwLjElPTAxJycnCmxpbmVzID0gcy5zcGxpdCgnXG4nKQpyZXMgPSBbXQpmb3IgbGluZSBpbiBsaW5lczoKCXJlcy5hcHBlbmQocmUuc3BsaXQocidccyo7JywgbGluZSlbMF0pCnByaW50KHJlcyk=