str.decode to PNG not working with MySql

[Tacllem]

Good day everyone.
I have inherited a Python 2.7 script that pulls records from a mysql database and creates png files to export my product's images. The line that worked for years is "fh.write(str.decode('base64'))" and the table "images" has a column named "imageFull" with a Collation of 'utf8_general_ci'

Last month the vendor updated the software and the table structure has changed. The column "imageFull" now has a Collation of 'utf8mb4_unicode_ci' and the write command fails. I tried updating to Python 3.13(64-bit)

I can't change the column structure as it is not my application. I can't say why they are storing images in this way. The vendor has no responsibility to helping with this export script.

So the question is "Do I need to use a decode other than 'base64'? Does it matter if i'm on python 2.7 or 3.13? Is there an alternate command to use for the write string? "


Here is a larger chunk of the code incase it helps.

try:	#Convert image string to its png form	print("Converting full size image...")	str = row[1]#full size image	fh = open(finalImageName, "wb")	fh.write(str.decode('base64'))	fh.close()	totalSuccessLarge+=1	except:	print("This large image failed...skipping and continuing process...")	totalFailLarge+=1	time.sleep(5)	pass	try:	print("Converting thumbnail size image...")	str = row[2]#thumb image	fh = open(finalImageName2, "wb") fh.write(str.decode('base64'))	fh.close()	totalSuccessThumb+=1	except:	print("This thumbnail image failed...skipping and continuing process...")	totalFailThumb+=1	time.sleep(5)	pass

Larz60+ write Oct-02-2024, 09:48 AM:
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[Tacllem]

Good morning.
The output of the script is as follows.

Part number for this image = zzz test part 1
Combined part num with .png = zzz test part 1.png
Final image name 2 (where small images are saved) = C:\Python27\thumbs\zzz test part 1.png
Converting full size image...
1
2
This large image failed...skipping and continuing process...
Converting thumbnail size image...
This thumbnail image failed...skipping and continuing process...
Moving large images into their folder...
PROCESS COMPLETE!
Large Image Success total = 0
Large Image Failed Total = 1
Thumb Image Success total = 0
Thumb Image Failed Total = 1

[snippsat]

Try use base64 module instead of str.decode('base64').
This should work for Python 3.13.

import base64 # Convert image string to bytes in base64, then decode str_data = row[1] # full-size image image_data = base64.b64decode(str_data) with open(finalImageName, "wb") as fh: fh.write(image_data)

Thumbnail conversion:

str_data_thumb = row[2] # thumbnail image thumb_image_data = base64.b64decode(str_data_thumb) with open(finalImageName2, "wb") as fh: fh.write(thumb_image_data)

You might need to encode it back to bytes before decoding from base64. For example:

str_data = row[1].encode('utf-8') # Ensure string is encoded as bytes image_data = base64.b64decode(str_data)

And try not to use str as variable name,Python use this name.

[Tacllem]

Hi.
Thank you for the suggestions. I beleve I implemented your changes. Unfortunately I still get the same error.

try:	#Convert image string to its png form	print("Converting full size image...")	str_data = row[1].encode('utf-8') # Ensure string is encoded as bytes	image_data = base64.b64decode(str_data)	#FB 19.7 was utf8_general_ci while FB 24.3 is utf8mb4_unicode_ci	with open(finalImageName, "wb") as fh: fh.write(image_data)	fh.close()	totalSuccessLarge+=1	except:

[snippsat]

I don't do consulting time,i can try to help you here on forum.
Try this code.

import base64 import time import mysql.connector from mysql.connector import errorcode import shutil import os import glob source_dir = "C:/python27" dst = 'C:/python27/largeSize' totalSuccessLarge = 0 totalFailLarge = 0 totalSuccessThumb = 0 totalFailThumb = 0 print("WELCOME TO SUPER MEGA AWESOME IMAGE CONVERTER!") # Load config variables configVariables = [] filepath = 'imgConvert-Config.txt' with open(filepath, 'r') as f: configVariables = f.readlines() print("Loading config file...") pw = os.environ.get('DB_PASSWORD') if not pw: raise ValueError("Database password not found in environment variables.") database = configVariables[0].strip() user = configVariables[1].strip() host = configVariables[2].strip() pathFull = configVariables[3].strip() pathSmall = configVariables[4].strip() print("Connecting to DB...") try: cnx = mysql.connector.connect(user=user, password=pw, host=host, port=3306, database=database) cursor = cnx.cursor() print("Executing queries...") sql_select_Query = "SELECT * FROM image" cursor.execute(sql_select_Query) records = cursor.fetchall() print("Total number of rows in image is - ", cursor.rowcount) for row in records: # Extract data img_id, full_size_image, thumbnail_image, record_id = row print(f"Id = {img_id}") print(f"Full Size image = {full_size_image}") print(f"Thumbnail image = {thumbnail_image}") print(f"recordID = {record_id}\n") # Get part number sql_select_Query3 = "SELECT num FROM part WHERE id = %s" cursor.execute(sql_select_Query3, (record_id,)) partNum = cursor.fetchone()[0] print(f"Part number for this image = {partNum}") # Prepare file paths finalImageName = os.path.join(dst, f"{partNum}.png") finalImageName2 = os.path.join(pathSmall, f"{partNum}.png") # Ensure directories exist os.makedirs(dst, exist_ok=True) os.makedirs(pathSmall, exist_ok=True) # Convert full-size image try: print("Converting full size image...") image_data = base64.b64decode(full_size_image) with open(finalImageName, "wb") as fh: fh.write(image_data) totalSuccessLarge += 1 except Exception as e: print(f"This large image failed... {e}") totalFailLarge += 1 continue # Convert thumbnail image try: print("Converting thumbnail size image...") thumb_image_data = base64.b64decode(thumbnail_image) with open(finalImageName2, "wb") as fh: fh.write(thumb_image_data) totalSuccessThumb += 1 except Exception as e: print(f"This thumbnail image failed... {e}") totalFailThumb += 1 continue except mysql.connector.Error as err: if err.errno == errorcode.ER_ACCESS_DENIED_ERROR: print("Something is wrong with your username or password") elif err.errno == errorcode.ER_BAD_DB_ERROR: print("Database does not exist") else: print(err) finally: if 'cursor' in locals(): cursor.close() if 'cnx' in locals(): cnx.close() print("PROCESS COMPLETE!") print(f"Large Image Success total = {totalSuccessLarge}") print(f"Large Image Failed Total = {totalFailLarge}") print(f"Thumb Image Success total = {totalSuccessThumb}") print(f"Thumb Image Failed Total = {totalFailThumb}")

[Tacllem]

Hi.
Thank you for helping. Your way of doing this is very interesting. Running this code I receive an error.

Executing queries...
Total number of rows in image is - 28345
Traceback (most recent call last):
File "C:\Python27\imageconverter-forum.py", line 46, in <module>
img_id, full_size_image, thumbnail_image, record_id = row
ValueError: too many values to unpack (expected 4)

[Tacllem]

Hi again. I have some progress.
If I remove the "= row" from the line "img_id, full_size_image, thumbnail_image, record_id = row" I get past this error.
Then at the top under the includes I add:

img_id = 0 full_size_image = "" thumbnail_image = "" record_id = 0

I get past the next error of "full_size_image" is not defined.

But then I hit the next landmine of:
Traceback (most recent call last):
File "C:\Python27\imageconverter-forum.py", line 60, in <module>
partNum = cursor.fetchone()[0]
TypeError: 'NoneType' object is not subscriptable

[snippsat]

Try before accessing the result, check if cursor.fetchone() returned a result:

cursor.execute(sql_select_Query3, (record_id,)) part_num_row = cursor.fetchone() if part_num_row: partNum = part_num_row[0] print(f"Part number for this image = {partNum}") else: print(f"No part number found for record ID {record_id}") totalFailLarge += 1 totalFailThumb += 1 continue # Skip to the next iteration

[Tacllem]

Hello.
I added that change and get hundreds of lines that say:

No part number found for record ID = 0
Id = 0
Full size image =
thumbnail =
recordID = 0

[snippsat]

Your image table may has entries where recordID is 0.
Since there is no part with id = 0, the query to get the partNum fails.
The full_size_image and thumbnail_image fields are empty (''), which means there's no image data to process.
Try this.

import base64 import mysql.connector from mysql.connector import errorcode import os source_dir = "C:/python27" dst = 'C:/python27/largeSize' totalSuccessLarge = 0 totalFailLarge = 0 totalSuccessThumb = 0 totalFailThumb = 0 print("WELCOME TO SUPER MEGA AWESOME IMAGE CONVERTER!") # Load config variables configVariables = [] filepath = 'imgConvert-Config.txt' with open(filepath, 'r') as f: configVariables = f.readlines() print("Loading config file...") pw = "xxxx9999" database = configVariables[0].strip() user = configVariables[1].strip() host = configVariables[2].strip() pathFull = configVariables[3].strip() pathSmall = configVariables[4].strip() print("Connecting to DB...") try: cnx = mysql.connector.connect(user=user, password=pw, host=host, port=3306, database=database) cursor = cnx.cursor() print("Executing queries...") # Modified SQL query to filter out invalid entries sql_select_Query = """ SELECT id, full_size_image, thumbnail_image, record_id FROM image WHERE record_id > 0 AND full_size_image IS NOT NULL AND full_size_image != '' AND thumbnail_image IS NOT NULL AND thumbnail_image != '' """ cursor.execute(sql_select_Query) records = cursor.fetchall() print("Total number of valid rows in image is - ", cursor.rowcount) for row in records: img_id, full_size_image, thumbnail_image, record_id = row print(f"Id = {img_id}") print(f"Full Size image = {full_size_image}") print(f"Thumbnail image = {thumbnail_image}") print(f"recordID = {record_id}\n") # Query for part number sql_select_Query3 = "SELECT num FROM part WHERE id = %s" cursor.execute(sql_select_Query3, (record_id,)) part_num_row = cursor.fetchone() if part_num_row: partNum = part_num_row[0] print(f"Part number for this image = {partNum}") else: print(f"No part number found for record ID = {record_id}") totalFailLarge += 1 totalFailThumb += 1 continue # Skip to the next image # Prepare file paths finalImageName = os.path.join(dst, f"{partNum}.png") finalImageName2 = os.path.join(pathSmall, f"{partNum}.png") # Ensure directories exist os.makedirs(dst, exist_ok=True) os.makedirs(pathSmall, exist_ok=True) # Convert full-size image try: print("Converting full size image...") image_data = base64.b64decode(full_size_image) with open(finalImageName, "wb") as fh: fh.write(image_data) totalSuccessLarge += 1 except Exception as e: print(f"This large image failed... {e}") totalFailLarge += 1 continue # Convert thumbnail image try: print("Converting thumbnail size image...") thumb_image_data = base64.b64decode(thumbnail_image) with open(finalImageName2, "wb") as fh: fh.write(thumb_image_data) totalSuccessThumb += 1 except Exception as e: print(f"This thumbnail image failed... {e}") totalFailThumb += 1 continue except mysql.connector.Error as err: if err.errno == errorcode.ER_ACCESS_DENIED_ERROR: print("Something is wrong with your username or password") elif err.errno == errorcode.ER_BAD_DB_ERROR: print("Database does not exist") else: print(err) finally: if 'cursor' in locals(): cursor.close() if 'cnx' in locals(): cnx.close() print("PROCESS COMPLETE!") print(f"Large Image Success total = {totalSuccessLarge}") print(f"Large Image Failed Total = {totalFailLarge}") print(f"Thumb Image Success total = {totalSuccessThumb}") print(f"Thumb Image Failed Total = {totalFailThumb}")