Because dictionaries are the built-in mapping type in Python. Print ( "StopIteration error:", err, "- rewinding Cursor object. The fastest way to repeatedly lookup data with millions of entries in Python is using dictionaries. However, dictionaries in Python do not allow duplicate keys. ![]() Print ( "Result object for find_one() query returned 'None'" ) As we know, a dictionary is a collection of elements that are ordered and can be modified. A list or array lets you access your data by a single. Print ( "KeyError ERROR for:", result, "-", err ) Dictionaries in Python are a well designed version of a very common data structure called a hash map. Print ( "The found_one() request returned ID:", id_found ) # check if the find_one() call returns 'None' # iterate over the document dictionaries in the list # get all the documents in a MongoDB collection with list() # create MongoDB database and collection instances yamlimport.py Imports the YAML module for use in our script import yaml Opens the file ex1.yaml, and loads the contents in the variable result with open ex1. # build a new client instance from the MongoClient class The easiest way to do this is to run a simple script that stores the contents of the file in a Python variable called ‘result’. Introduction Prerequisites Connect to the MongoDB Server using the MongoClient class in Python Access a MongoDB database and collection using the Python client instance Access a MongoDB database using the PyMongo client instance Access the Collection attribute of the MongoDB database instance Use a Python iterator to access all of a MongoDB collection’s documents Make a list of all the IDs returned in a PyMongo API call to a MongoDB collection Get all attributes of a MongoDB collection object in Python All of the Python methods used to find documents in a MongoDB collection Use Python’s list() function to return a list of all the MongoDB documents in a collection Access the items for each MongoDB document’s dictionary Find a MongoDB document in Python using the find_one() method Check if the Cursor object returned by the MongoDB API request is Python “NoneType” object Check the length of the object returned by the MongoDB API call Using the Cursor object’s next() method to iterate over documents in PyMongo How to catch and avoid the StopIteration error raised by the PyMongo Cursor object Iterate over a PyMongo Cursor object returned by a MongoDB API call Iterate over the MongoDB result object’s items Conclusion You can use dict() function along with the zip() function, to combine separate lists of keys and values obtained dynamically at runtime.
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