Menu
I'm trying to set up a choice field in django, but I don't think this is a django issue. The choices field takes an iterable (e.g., a list or tuple) of 2-tuples to use as choices for this field.
Here's my code:
self.fields['question_' + question.id] = forms.ChoiceField(
label=question.label,
help_text=question.description,
required=question.answer_set.required,
choices=[("fe", "a feat"), ("faaa", "sfwerwer")])
for some reason, i always get the following error:
TypeError - cannot concatenate 'str' and 'long' objects
The last line is always highlighted.
I'm not trying to concatenate anything. Almost regardless of what I change the list to for the 'choices' parameter, I get this error.
What's going on?
561
In Python, we cannot concatenate a string and an integer together. They have a different base and memory space as they are completely different data structures.
Python does not support the auto type of the variable to be cast. You can not concatenate an integer value to a string. The root cause of this issue is due to the concatenation between an integer value and a string object. Before concatenation, an integer value should be converted to a string object.
The Python "TypeError: can only concatenate str (not "NoneType") to str" occurs when we try to concatenate a string and a None value. To solve the error, correct the assignment or check if the variable doesn't store a None value before concatenating.
Most likely it's highlighting the last line only because you split the statement over multiple lines.
The fix for the actual problem will most likely be changing
self.fields['question_' + question.id]
to
self.fields['question_' + str(question.id)]
As you can quickly test in a Python interpreter, adding a string and a number together doesn't work:
>>> 'hi' + 6
Traceback (most recent call last):
File "<pyshell#0>", line 1, in <module>
'hi' + 6
TypeError: cannot concatenate 'str' and 'int' objects
>>> 'hi' + str(6)
'hi6'
'question_' is a string, question.id is a long. You can not concatenate two things of different types, you will have to convert the long to a string using str(question.id).
28
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
