<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def write_text(filename, data, add=False):
 """ Write image data to text file :param filename: name of text file to write data to :type filename: str :param data: image data to write to text file :type data: numpy array :param add: whether to append to existing file or not. Default is ``False`` :type add: bool """

    write_type = 'a' if add else 'w'
    with open(filename, write_type) as file:
        print(data, end='', file=file)