What is an InstrumentedList in Python?
Question:
During some set operations I encountered this error in Python:
TypeError: unhashable type: 'InstrumentedList'
What is an InstrumentedList in Python? I only found a few references related to SQLAlchemy. Is this a SQLAlchemy implementation of lists or something?
By the way, it happens while doing:
set(self.some_list)
where
print type(self.some_list) # <type 'list'>
Answers:
Yes it’s part of SQLAlchemy API. Here is the class reference:
Yes, SQLAlchemy uses it to implement a list-like object which is aware of insertions and deletions of related objects to an object (via one-to-many and many-to-many relationships).
During some set operations I encountered this error in Python:
TypeError: unhashable type: 'InstrumentedList'
What is an InstrumentedList in Python? I only found a few references related to SQLAlchemy. Is this a SQLAlchemy implementation of lists or something?
By the way, it happens while doing:
set(self.some_list)
where
print type(self.some_list) # <type 'list'>
Yes it’s part of SQLAlchemy API. Here is the class reference:
Yes, SQLAlchemy uses it to implement a list-like object which is aware of insertions and deletions of related objects to an object (via one-to-many and many-to-many relationships).