TypeError: argument of type 'datetime.date' is not iterable when trying to print a document

ERPNext
1

Expected Behaviour
Print a document according to a custom or standard print format.

Actual Behaviour
Displays the following error when trying to print a document(for both standard and custom print formats):

Traceback (most recent call last):
File “/home/frappe/frappe-bench/apps/frappe/frappe/website/render.py”, line 39, in render
data = render_page_by_language(path)
File “/home/frappe/frappe-bench/apps/frappe/frappe/website/render.py”, line 134, in render_page_by_language
return render_page(path)
File “/home/frappe/frappe-bench/apps/frappe/frappe/website/render.py”, line 150, in render_page
return build(path)
File “/home/frappe/frappe-bench/apps/frappe/frappe/website/render.py”, line 157, in build
return build_page(path)
File “/home/frappe/frappe-bench/apps/frappe/frappe/website/render.py”, line 171, in build_page
if context.title and “{{” in context.title:
TypeError: argument of type ‘datetime.date’ is not iterable

Steps to reproduce:
I am working on a custom docType called ‘Employment Tax’ that calculates tax and related information. I have completed my work on the docType as it produced the intended result. But I keep getting the error message that I showed above when I try to prepare a custom print format that fetches some calculated values and parameters like date_of_joining and work_tax from the docType and populates fields and tables that I’ve prepared in the print format.

So, the steps to reproduce the issue are:

  1. Create a new Employment Tax document
  2. Fill out the necessary fields including child tables
  3. Save and print the document
    Frappé version: v9.1.5
    ERPNext version: v9.1.3
2

Can you post your Custom Print format. Looks like it is expecting a string where you are passing a datetime object.
You could try converting your datetime fields to string in the custom print format e.g.

doc.date_of_joining.strftime('%d/%m/%Y')
3

Coincidentally same general problem here!? Event Data Import argument of type ‘datetime.datetime’ is not iterable - #4 by clarkej

4

@vijaywm Thank you for your reply.

I think I found the problem. While making the doctype, I had the ‘Title Field’ of the doctype set to ‘end_date’ because I wanted the documents to be listed by their end dates. When I change this to the ‘company’ field name, it works(i.e. the printing works). But I don’t know what this has to do with the custom print format because I haven’t even used the ‘end_date’ field name in the custom print format. Besides, I have no fields of type datetime. It would be great if someone can explain this.

5 
if context.title and “{{” in context.title:

this is looking for a string value in context.title, where you have a datetime. I guess it means only strings are allowed in Title.

6

Thanks, @vijaywm.
Now it makes sense.