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UnicodeDecodeError: 'utf-8' codec can't decode byte 0x89 in position 0: invalid start byte

Terry Reedy tjreedy at udel.edu
Thu Dec 6 05:29:04 EST 2012 
On 12/6/2012 5:07 AM, iMath wrote:
> the following code originally from http://zetcode.com/databases/mysqlpythontutorial/
> within the "Writing images" part .
>
>
> import MySQLdb as mdb

Not part of stdlib. 'MySQLdb' should be in the subject line to get 
attention of someone who is familiar with it. I am not.

> import sys
>
> try:
>      fin = open("Chrome_Logo.svg.png",'rb')
>      img = fin.read()
>      fin.close()
>
> except IOError as e:
>
>      print ("Error %d: %s" % (e.args[0],e.args[1]))
>      sys.exit(1)
>
>
> try:
>      conn = mdb.connect(host='localhost',user='testuser',
>         passwd='test623', db='testdb')
>      cursor = conn.cursor()
>      cursor.execute("INSERT INTO Images SET Data='%s'" % \
>          mdb.escape_string(img))

 From the name, I would expect that excape_string expects text. From the 
error, it seems to specifically expect utf-8 encoded bytes. After 
decoding, I expect that it does some sort of 'escaping'. An image does 
not qualify as that sort of input. If escape_string takes an encoding 
arg, latin1 *might* work.

>      conn.commit()
>
>      cursor.close()
>      conn.close()
>
> except mdb.Error as e:
>
>      print ("Error %d: %s" % (e.args[0],e.args[1]))
>      sys.exit(1)
>
>
> I port it to python 3 ,and also change
> fin = open("chrome.png")
> to
> fin = open("Chrome_Logo.png",'rb')
> but when I run it ,it gives the following error :
>
> Traceback (most recent call last):
>    File "E:\Python\py32\itest4.py", line 20, in <module>
>      mdb.escape_string(img))
> UnicodeDecodeError: 'utf-8' codec can't decode byte 0x89 in position 0: invalid start byte
>
> so how to fix it ?
>


-- 
Terry Jan Reedy
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