"Python Cookbook" "Data Structure and algorithm" 9. Find the same point in two dictionaries

Problem: Look for two dictionaries in the middle of the same place (same key, same value, etc.)

Solution: Use the keys () or the items () method to perform common collection operations (such as seek a set, intersection, and difference sets)

>>> a={'x': 1,'y': 2,'Z': 3}>>> b={'ww': 10,'x': 11,'y': 2}>>> A.keys () &B.keys () #键的交集 {'y','x'}>>> A.keys ()-B.keys () #键的差集 {'Z'}>>> A.keys () |B.keys () #键的并集 {'ww','y','x','Z'}>>> A.items () &B.items () {('y', 2)}>>> A.items ()-B.items () {('Z', 3), ('x', 1)}>>> A.items () |B.items () {('ww', 10), ('Z', 3), ('x', 1), ('x', 11), ('y', 2)}>>>

These types of operations can also be used to modify or filter out the contents of a dictionary. For example:

 for  in A.keys ()-{'w','z'}}  #  Create a new dictionary with some keys removed >>> c{'y'x' : 1}

Summarize:

The keys () method of the dictionary, the items () method supports collection operations, but the values () method is not supported. Because there is no guarantee that all values are unique in the dictionary from a value perspective, this can cause problems with some collection operations. However, you can do this by turning values into collections.

"Python Cookbook" "Data Structure and algorithm" 9. Find the same point in two dictionaries