import re
text = """I am: "eating", mango
I am: eating a pine apple; and mango"""
rx = re.compile(r'^(I am:\s*)("[^"]*"|[^;]*)')
for line in text.splitlines():
m = rx.search(line)
if m:
print("{}{}".format(m.group(1), m.group(2).strip('"')))
aW1wb3J0IHJlCnRleHQgPSAiIiJJIGFtOiAiZWF0aW5nIiwgbWFuZ28KSSBhbTogZWF0aW5nIGEgcGluZSBhcHBsZTsgYW5kIG1hbmdvIiIiCnJ4ID0gcmUuY29tcGlsZShyJ14oSSBhbTpccyopKCJbXiJdKiJ8W147XSopJykKZm9yIGxpbmUgaW4gdGV4dC5zcGxpdGxpbmVzKCk6CgltID0gcnguc2VhcmNoKGxpbmUpCglpZiBtOgoJCXByaW50KCJ7fXt9Ii5mb3JtYXQobS5ncm91cCgxKSwgbS5ncm91cCgyKS5zdHJpcCgnIicpKSk=