I'm trying to create a custom template tag which takes 3 arguments. I'm trying to calculate the number of days between two dates, while excluding the weekends days from that count. And depending on the department, the weekend is different for each user. So I need start_date, end_date, user_id to be passed onto the template tag function. This is what I have done so far:
from django import template
from datetime import datetime, timedelta, date
register = template.Library()
@register.filter('date_diff_helper')
def date_diff_helper(startdate, enddate):
return [startdate, enddate]
@register.filter(name='date_diff')
def date_diff(dates, user_id):
start_date = dates[0]
end_date = dates[1]
count = 0
weekends = ["Friday", "Saturday"]
for days in range((end_date - start_date).days + 1):
if start_date.strftime("%A") not in weekends:
count += 1
else:
start_date += timedelta(days=1)
continue
if start_date == end_date:
break
start_date += timedelta(days=1)
return count
This is how I'm calling these functions in template:
{{ leave.start_date|date_diff_helper:leave.end_date|date_diff:leave.emp_id }}
When I run the code, it gives me TypeError saying 'datetime.date' object is not subscriptable. When I tried to check the type of dates parameter in date_diff function, it says:
< class 'list'>
< class 'datetime.date'>
But when it tries to assign start_date as the first date object, as in start_date = dates[0], it throws the error even. Here is a complete traceback of the error:
Traceback:
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\core\handlers\exception.py" in inner
34. response = get_response(request)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\core\handlers\base.py" in _get_response
115. response = self.process_exception_by_middleware(e, request)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\core\handlers\base.py" in _get_response
113. response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\views\generic\base.py" in view
71. return self.dispatch(request, *args, **kwargs)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\views\generic\base.py" in dispatch
97. return handler(request, *args, **kwargs)
File "C:\Projects\LMS\LMSAdmin\views.py" in get
203. return render(request, self.template_name, {'leave_requests': leave_requests})
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\shortcuts.py" in render
36. content = loader.render_to_string(template_name, context, request, using=using)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\loader.py" in render_to_string
62. return template.render(context, request)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\backends\django.py" in render
61. return self.template.render(context)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render
171. return self._render(context)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in _render
163. return self.nodelist.render(context)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render
937. bit = node.render_annotated(context)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render_annotated
904. return self.render(context)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\loader_tags.py" in render
150. return compiled_parent._render(context)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in _render
163. return self.nodelist.render(context)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render
937. bit = node.render_annotated(context)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render_annotated
904. return self.render(context)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\loader_tags.py" in render
62. result = block.nodelist.render(context)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render
937. bit = node.render_annotated(context)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render_annotated
904. return self.render(context)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\defaulttags.py" in render
209. nodelist.append(node.render_annotated(context))
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render_annotated
904. return self.render(context)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in render
987. output = self.filter_expression.resolve(context)
File "C:\Users\Naeem.Khan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\django\template\base.py" in resolve
698. new_obj = func(obj, *arg_vals)
File "C:\Projects\LMS\LMSAdmin\templatetags\LMSAdmin_tags.py" in date_diff
38. start_date = dates[0]
Exception Type: TypeError at /lms_admin/SeniorManagementAdmin/
Exception Value: 'datetime.date' object is not subscriptable
I'm a beginner to Django and Python.
This is how I checked the type of dates variable:
def date_diff(dates, user_id):
print(type(dates))
#if I removed these two lines, the result is only < class 'list'>
start_date = dates[0]
end_date = dates[1]
...
When I visit the page, it prints out in console that the type is list and datetime. But if I remove the above start_date and end_date variables, it prints out < class 'list'> only. I do not understand this behavior.
When I run the code, it gives me TypeError saying 'datetime.date' object is not subscriptable. When I tried to check the type of dates parameter in date_diff function, it says:
< class 'list'>
< class 'datetime.date'>
This suggests that you actually have two calls to the filter in your template - the first one being correct and the second one incorrect.