Reading unicode from sqlite db using python

The data stored in unicode (in database) has to be retrieved and convert into a different form.

The following snippet

def convert(content):
    content = content.replace("ஜௌ", "n\[s");
    return content;

mydatabase = "database.db"
connection = sqlite3.connect(mydatabase)
cursor = connection.cursor()
query = ''' select unicode_data from table1'''
cursor.execute(query)
for row in cursor.fetchone():
    print convert(row)

yields the following error message in convert method.

exceptions.UnicodeDecodeError: 'ascii' codec can't decode byte 0xe0 in position 0: ordinal not in range(128)

If the database content is "ஜௌஜௌஜௌ", the output should be "n\[sn\[sn\[s"

The documentation suggests to use ignore or replace to avoid the error, when creating the unicode string.

when the iteration is changed as follows:

for row in cursor.fetchone():
    print convert(unicode(row, errors='replace'))

it returns

exceptions.TypeError: decoding Unicode is not supported

which informs that row is already a unicode.

Any light on this to make it work is highly appreciated. Thanks in advance.