如何高效使用PyMongo cursor

Question

Please propose ways to access data returned from collections.find() in an efficient manner.

Is a for iteration the recommended way? How do I keep the character of a cursor being an Iterable ?

Thx

Answer 1

There are several ways to efficiently access the data returned by a PyMongo cursor:

1. Iterating through the cursor: You can iterate through the cursor using a for loop, as you mentioned. This is a simple and easy way to access the data, but it can be inefficient if the cursor returns a large amount of data, as the entire dataset will be loaded into memory.

2. Using the limit() method: You can use the limit() method to limit the number of documents returned by the cursor, which can be useful if you only need to access a small subset of the data.

3. Using the batch_size() method: You can use the batch_size() method to specify the number of documents the cursor should return in each batch. This can be more efficient than iterating through the entire cursor at once, as it reduces the amount of data that needs to be loaded into memory at any given time.

4. Using the skip() method: You can use the skip() method to skip a certain number of documents in the cursor before returning the rest of the documents. This can be useful if you only want to access a specific subset of the data.

Regardless of the method you choose, the cursor will maintain its iterable character and you can continue to use it as an iterable object.

Answer 2

A simple:

A cursor implements methods of Iterable and Iterator and behaves as such, would have been the answer.

(after diving into the code of PyMongo's cursor.py )