password validation and exception

backend/utils/utils.py

@@ -31,3 +31,53 @@ def is_valid_email(email):
         return True
     else:
         return False
+    
+def password_check(passwd: str) -> bool:
+    special_symbol_pattern = r'[$@#%]'
+    upper_case_pattern = r'[A-Z]'
+    lower_case_pattern = r'[a-z]'
+    digit_pattern = r'[0-9]'
+    
+    if len(passwd) < 6:
+        raise PasswordLengthMinException('Password length should be at least 6 characters.')
+    elif len(passwd) > 20:
+        raise PasswordLengthMaxException('Password length should not be greater than 20 characters.')
+
+    if not re.search(digit_pattern, passwd):
+        raise PasswordNumericException('Password should have at least one numeral.')
+
+    if not re.search(upper_case_pattern, passwd):
+        raise PasswordUppercaseException('Password should have at least one uppercase letter.')
+
+    if not re.search(lower_case_pattern, passwd):
+        raise PasswordLowercaseException('Password should have at least one lowercase letter.')
+
+    if not re.search(special_symbol_pattern, passwd):
+        raise PasswordSpecialSymbolException('Password should have at least one of the symbols $@#%.')
+
+    return True
+
+
+class PasswordLengthMinException(Exception):
+    def __init__(self, message):
+        self.message = message
+
+class PasswordLengthMaxException(Exception):
+    def __init__(self, message):
+        self.message = message
+
+class PasswordNumericException(Exception):
+    def __init__(self, message):
+        self.message = message
+
+class PasswordUppercaseException(Exception):
+    def __init__(self, message):
+        self.message = message
+
+class PasswordLowercaseException(Exception):
+    def __init__(self, message):
+        self.message = message
+
+class PasswordSpecialSymbolException(Exception):
+    def __init__(self, message):
+        self.message = message