Typeerror: document must be an instance of dict, bson.son.son, bson.raw_bson.rawbsondocument, or a type that inherits from collections.mutablemapping

Error: TypeError

The error message “document must be an instance of dict, bson.son.son, bson.raw_bson.rawbsondocument, or a type that inherits from collections.mutablemapping” typically occurs when trying to perform an operation on a document variable that is not of the correct type.

Explanation:

In Python, the error message indicates that the document object being used must be an instance or subclass of dict, bson.son.SON, bson.raw_bson.RawBSONDocument, or a type that inherits from collections.MutableMapping. This requirement usually arises in scenarios where working with MongoDB or BSON data.

Examples:

1. Example 1:

   
   document = 123
   result = document['key']
         

   In this example, the variable document is assigned the integer value 123 instead of a valid document type. When trying to access the value associated with the key 'key', a TypeError will be raised because an integer does not support item access like a dictionary or mapping type would.

2. Example 2:

   
   import bson
   document = bson.int64.Int64(42)
   result = document['key']
         

   Here, the bson.int64.Int64 type from the PyMongo library is used, which is not a valid document type. Similar to the previous example, attempting to access 'key' from document will generate a TypeError.

Solution:

To resolve this error, ensure that the document variable is assigned a valid document object, such as a dictionary or an appropriate subclass. Make sure the variable is not mistakenly assigned a different type.