isbnlib always returns HTTP 429 when accessing Google Books[BUG]

[seanboyce]

Describe the bug
I am receiving HTTP 429 errors when requesting book metadata via Google Books. This happens 100% of the time, and regardless of request frequency (I make one request every few minutes at maximum). Other data sources (wiki, openl) are working fine.

To Reproduce

I have isbnlib==3.10.14 and Python 3.10.12

My test script follows. It returns a HTTP 429 error for google books, other services work normally:

from isbnlib import *
isbn ='9786586691627'
book = {}
try:
    book = meta(isbn,service='goob')
    print(book)
except Exception as e:
    print("Google Books API failed with response: " )
    print(e)
try:
    if len(book)==0:
        book = meta(isbn,service="openl")
except Exception as e:
    print("Open Library API failed with response: " )
    print(e)
try:
    if len(book)==0:
        book = meta(isbn,service='wiki')
except Exception as e:
    print("Wikipedia API failed with response: " )
    print(e)
if len(book)==0:
    raise LookupError(f"Book with isbn {isbn} not found!")
#else:
#    print(book)

Additional context
I am located in Viet Nam. I've tried running from both a residential IP address and my VPS. I've never encountered a geoblocking issue with google books before, but I can't rule it out either. Let me know if any other information I can provide.

[seanboyce]

The root cause is that Google Books is not working reliably for me unless I specify an API key.

Meanwhile, if I specify an API key using config.add_apikey(service, apikey), isbnlib doesn't pick it up and use it in meta() or desc().

For anyone else encountering this issue, it is fixed in the fork isbnlib2 here: https://github.com/hans-fritz-pommes/isbnlib