Write a function to check that the given string contains only a certain set of characters(in this case a-z, a-z and 0-9) by using regex.
import re
def is_allowed_specific_char(string):
    get_char = re.compile(r'[^a-zA-Z0-9.]')
    string = get_char.search(string)
    return not bool(string)
<s>[INST]<<SYS>>Given a task and its code, generate test cases for the code.<</SYS>>Write a function to check that the given string contains only a certain set of characters(in this case a-z, a-z and 0-9) by using regex.
import re
def is_allowed_specific_char(string):
    get_char = re.compile(r'[^a-zA-Z0-9.]')
    string = get_char.search(string)
    return not bool(string)[/INST]assert is_allowed_specific_char("ABCDEFabcdef123450") == True
assert is_allowed_specific_char("*&%@#!}{") == False
assert is_allowed_specific_char("HELLOhowareyou98765") == True</s>