(string)
return None
Method to check if a given string contains one of the operation signs.

    :param string: given string
    :return: operation index in list of pre-defined list of operations or
    Null if string does not contain any
Method to check if a given string contains one of the operation signs.
Method to check if a given string contains one of the operation signs .
def contains_operation(string):
    """
    Method to check if a given string contains one of the operation signs.

    :param string: given string
    :return: operation index in list of pre-defined list of operations or
    Null if string does not contain any
    """
    for i in range(len(operationSign)):
        if string.find(operationSign[i]) != -1:
            return i
    return None
def contains_operation ( string ) : for i in range ( len ( operationSign ) ) : if string . find ( operationSign [ i ] ) != - 1 : return i return None