Expressão regular caracteres especiais
String regExp = "^[^<>{}\"/|;:.,~!?@#$%^=&*\\]\\\\()\\[¿§«»ω⊙¤°℃℉€¥£¢¡®©0-9_+]*$";
Disturbed Dog
String regExp = "^[^<>{}\"/|;:.,~!?@#$%^=&*\\]\\\\()\\[¿§«»ω⊙¤°℃℉€¥£¢¡®©0-9_+]*$";
#### ? designates an optional group. It can appear once or not at all
RegEx = re.compile(r'(good)?bye')
mo = RegEx.search("bye bye bye")
mo.group()