Regex pattern sanitization for wildcard replacement

I need a function to sanitize regex patterns in Python, specifically targeting strings that may contain wildcard characters (%). The goal is to replace these % wildcards with the regex equivalent .*? to allow for flexible matching in regex patterns. Additionally, the function should ensure that special regex characters are escaped appropriately without adding unnecessary escape characters.

Requirements:

1. Convert % to .*? in the provided regex patterns.
2. Escape special regex characters only when necessary, avoiding unnecessary escape sequences.
3. Maintain the integrity of existing regex patterns.

Examples:

1. Input: %core account.*?Annual Percentage Yield%

   exp Output: .*?core account.*?Annual Percentage Yield.*?

   String: Your core account offers an Annual Percentage Yield of 3.25%. This account is ideal for saving.

2. Input: interest rate on your account ((\d+\.\d+)|[^.])*?([\d+.]+%)

   Output: interest rate on your account ((\d+\.\d+)|[^.])*?([\d+.]+.*?)

   String: The interest rate on your account is 1.75%, while promotional rates are as high as 2.00%.

few more inputs:

1: Overdraft Protection Service Fee[^.]*?(\\$\\d+)

2: APY was accurate as of ([^\\s]+)

3: Cuenta de Ahorro opcional 6Obtenga hasta un ([^\\s]*) de porcentaje de rendimiento anual

4: \\bVisa\\b

5: withdrawals(.*?) per day

6: ([^a-zA-Z\\s]+) total is calculated based on all withdrawals

7: activate .*? calling ([^\\s]+)

I tried the following approach:

def _sanitize_regex(rhs: string):
    # Replace '%' wildcards with '.*?' for regex matching
    rhs = rhs.replace('%', '.*?')

    # Define special characters that need to be escaped in regex
    special_chars = ['$', '^', '[', ']', '{', '}', '|', '+', '<', '>', '\\']
    
    sanitized_rhs = []
    inside_group = False  # Track whether we're inside a group (e.g., parentheses or brackets)

    for char in rhs:
        # Handle opening and closing of groups
        if char in ['(', '[', '{']:
            inside_group = True
            sanitized_rhs.append(char)
        elif char in [')', ']', '}']:
            inside_group = False
            sanitized_rhs.append(char)
        # Escape special characters only if they are not inside a group
        elif char in special_chars:
            if not inside_group:  # Only escape if we are not inside a group
                sanitized_rhs.append(f"\\{char}")
            else:
                sanitized_rhs.append(char)  # Do not escape inside groups
        else:
            sanitized_rhs.append(char)

    # Join sanitized parts back together
    return ''.join(sanitized_rhs)

But it did not work for the following inputs:

2. interest rate on your account ((\d+.\d+)|[^.])*?([\d+.]+%)

output: interest rate on your account ((\d+\.\d+)\|[^.])*?([\d+.]\+.*?)

extra \ was being added by the above code. Can you help me sanitize the strings to get valid regex, considering the above requirements?

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