import re
r = re.compile(r'[<>%;$]') # Regex matching the specific characters
chars = set('<>%;$')       # Define the set of chars to check for
 
def checkString(s):
	if any((c in chars) for c in s): # If we found the characters in the string
		return False                 # It is invalid, return FALSE
	else:                            # Else
		return True                  # It is valid, return TRUE
 
def checkString2(s):
	if r.search(s):   # If we found the "bad" symbols
		return False  # Return FALSE
	else:             # Else
		return True   #  Return TRUE
 
s = 'My bad <string>'
print(checkString(s))
print(checkString2(s))
s = 'My good string'
print(checkString(s))
print(checkString2(s))

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