# Getting an error when i try to instantiate\_certificate\_batch.py in cert\_tools repo

**URL:** <https://community.blockcerts.org/t/getting-an-error-when-i-try-to-instantiate-certificate-batch-py-in-cert-tools-repo/3435>\
**Category:** Technical\
**Created:** [July 5, 2023, 11:37am UTC](https://community.blockcerts.org/t/getting-an-error-when-i-try-to-instantiate-certificate-batch-py-in-cert-tools-repo/3435 "2023-07-05T11:37:50Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![josephwambicho](https://avatars.discourse-cdn.com/v4/letter/j/dfb087/32.png) [@josephwambicho](https://community.blockcerts.org/u/josephwambicho)\
**Post date:** [July 5, 2023, 11:37am UTC](https://community.blockcerts.org/t/getting-an-error-when-i-try-to-instantiate-certificate-batch-py-in-cert-tools-repo/3435/1 "2023-07-05T11:37:50Z")

</div>

when i run “instantiate-certificate-batch -c conf.ini” in the cert\_tools repository iam getting this error  
raceback (most recent call last):  
File “/home/jose/.local/bin/instantiate-certificate-batch”, line 8, in   
sys.exit(main())  
File “/home/jose/.local/lib/python3.10/site-packages/cert\_tools/instantiate\_v3\_certificate\_batch.py”, line 131, in main  
instantiate\_batch(conf)  
File “/home/jose/.local/lib/python3.10/site-packages/cert\_tools/instantiate\_v3\_certificate\_batch.py”, line 97, in instantiate\_batch  
certs = create\_unsigned\_certificates\_from\_roster(template, recipients, use\_identities, config.additional\_per\_recipient\_fields)  
File “/home/jose/.local/lib/python3.10/site-packages/cert\_tools/instantiate\_v3\_certificate\_batch.py”, line 56, in create\_unsigned\_certificates\_from\_roster  
issued\_on = helpers.create\_iso8601\_tz()  
File “/home/jose/.local/lib/python3.10/site-packages/cert\_tools/helpers.py”, line 61, in create\_iso8601\_tz  
return ret.isoformat()  
AttributeError: ‘str’ object has no attribute ‘isoformat’. Did you mean: ‘format’?  
what could be the problem?

---

<div class="post-metadata">

**Author:** ![lemoustachiste](https://avatars.discourse-cdn.com/v4/letter/l/7c8e57/32.png) [@lemoustachiste](https://community.blockcerts.org/u/lemoustachiste)\
**Post date:** [July 5, 2023, 1:38pm UTC](https://community.blockcerts.org/t/getting-an-error-when-i-try-to-instantiate-certificate-batch-py-in-cert-tools-repo/3435/2 "2023-07-05T13:38:17Z")

</div>

cert\_tools has received very little attention in the past years and may not be the most reliable library offered by blockcerts.

As it seems, there is a python error where the type of the value does not have the `isoformat` method (since it seems it is a string).