solving <type 'exceptions.KeyError'> '\x00'

[mostwanted]

Hi guys, today I encountered this error: <type 'exceptions.KeyError'> '\x00', I think it occured during shut down because wheni rebooted my laptop it was there, in chapter 6 of the book (fixing migrations) it says we should add db.define_table(...., migrate=True, fake_migrate=True) but when I did that the error still persists it doesnt go anywhere, I then added migrate=False alone in the tables that came up in the issued TICKETS and the app was good and running, why is this and what is the difference between

adding db.define_table(...., migrate=True, fake_migrate=True) and just adding

db.define_table(...., migrate=True)?


Regards;


Mostwanted

[Jim S]

Can you post a more complete traceback?

[mostwanted]

Hey Jim, thats the traceback below:

Traceback

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

Traceback (most recent call last):   File "C:\Users\Maswabi\Desktop\WEB2PY APPLICATIONS\web2py-2.20.4\gluon\restricted.py", line 219, in restricted     exec(ccode, environment)   File "C:/Users/Maswabi/Desktop/WEB2PY APPLICATIONS/web2py-2.20.4/applications/wah/models/dbmanaq.py", line 54, in <module>     format='%(product)s')   File "C:\Users\Maswabi\Desktop\WEB2PY APPLICATIONS\web2py-2.20.4\gluon\packages\dal\pydal\base.py", line 657, in define_table     table = self.lazy_define_table(tablename, *fields, **kwargs)   File "C:\Users\Maswabi\Desktop\WEB2PY APPLICATIONS\web2py-2.20.4\gluon\packages\dal\pydal\base.py", line 698, in lazy_define_table     polymodel=polymodel,   File "C:\Users\Maswabi\Desktop\WEB2PY APPLICATIONS\web2py-2.20.4\gluon\packages\dal\pydal\adapters\base.py", line 913, in create_table     return self.migrator.create_table(*args, **kwargs)   File "C:\Users\Maswabi\Desktop\WEB2PY APPLICATIONS\web2py-2.20.4\gluon\packages\dal\pydal\migrator.py", line 323, in create_table     sql_fields_old = pickle.load(tfile)   File "pickle.py", line 1384, in load   File "pickle.py", line 864, in load KeyError: '\x00'

I really wanna fully understand this error & the best way to solve it because I have encountered it in the past & it always became a struggle, it turned into a nightmare that I started to dread it with every application i developed especially standalone applications which can be affected by sudden powercuts in computers without UPS or laptops with batter batteries!

[Jim S]

I am definitely not an expert on this, but it looks to me like you have some data in one of your tables that python cannot pickle.  I'm guessing you have some unicode characters that snuck into your db.  Can you write a quick python script to scan through the data in all your tables to see which records won't pickle?

-Jim

[mostwanted]

Thank you Jim, so much