Feb 16, 2018 · Python dictionary is a built-in type that supports key-value pairs. It's the nearest builtin data structure relative to Java's HashMap.

Aug 16, 2011 · In Python 3.7, it looks like there are 2E20 minus 1 possible hash values, in fact. From -1E20 minus 1 to (+)1E20 minus 1. Try hash('I wandered lonely as a cloud, that drifts on high o\'er vales and hills, when all at once, I saw a crowd, a host of golden daffodils.')

Jun 21, 2009 · Another efficient way of doing this with the update method is with keyword arguments, but since they have to be legitimate python words, you can't have spaces or special symbols or start the name with a number, but many consider this a more readable way to create keys for a dict, and here we certainly avoid creating an extra unnecessary dict:

Jan 3, 2018 · Is there any HashSet implementation in Python? I know HashTable can be represented using dictionaries, but how do we represent HashSet implementation. I am NOT looking for a data structure with the same methods as HashSets but rather someone with a CONSTANT lookup time, or the order of O(1);

Aug 1, 2016 · You can make that slightly neater by using a defauldict instead of a plain dict. There's also a Counter class, which has some powerful methods, but it runs a little slower, so if speed's an issue use defaultdict, unless you want to use those Counter methods.

Jul 31, 2023 · Python's dict class is an implementation of what the Python documentation informally calls "mapping types". Internally, dict is implemented using a hashtable. Java's HashMap class is an implementation of the Map interface. Internally, HashMap is implemented using a hashtable.

Mar 18, 2010 · In Python, a) There is no concept of "primitive data types". int , float , and bool instances are real Python objects, and b) objects of these types are not implicitly copied when you pass them, not at a semantic Python level for sure and …

Sep 12, 2019 · make an empty dictionary, we also do the same with lists >>> counts = {} create a for loop that will count for the occurrences of the "key", for each occurrence we add 1. for element in elements: if element in counts: counts[element] +=1

Feb 5, 2017 · @ripper234: This closed question will indeed make it easier for future searches to find the answered question, but that doesn't make the question all that valuable in and of itself. – Steven Rumbalski

I'm doing this switchboard thing in python where I need to keep track of who's talking to whom, so if Alice --> Bob, then that implies that Bob --> Alice. Yes, I could populate two hash maps, but I'm wondering if anyone has an idea to do it with one. Or suggest another data structure. There are no multiple conversations.