str = \'{\"name\": \"John\", \"company\": \"AB\"C corp\", \"id\": \"12g: \"123 12-12\"}\'
B\"C replace with empty string \'\'
B\"C
Do you mean \W"\W and \w: "\d are the only cases you're worrying about?
\W"\W
\w: "\d
Then try this:
str = re.sub(r'([a-zA-Z](\: )?"[A-Z0-9])', "", str)