python Programming Glossary: hashable

http://stackoverflow.com/questions/1151658/python-hashable-dicts

hashable dicts As an exercise and mostly for my own amusement I'm implementing.. recent call last File stdin line 1 in module TypeError unhashable type 'dict' I guess it has to be tuples all the way down. Now.. key value but we're all adults here. class hashdict dict hashable dict implementation suitable for use as a key into other dicts...

Python most common element in a list

http://stackoverflow.com/questions/1518522/python-most-common-element-in-a-list

common element in a Python list My list items may not be hashable so can't use a dictionary. Also in case of draws the item with.. nobody's proposed what I'd consider an obvious one for non hashable but comparable elements itertools.groupby 1 . itertools offers..

Using a Python Dictionary as a Key (Non-nested)

http://stackoverflow.com/questions/1600591/using-a-python-dictionary-as-a-key-non-nested

as keys The general problem with more complicated non hashable objects and my specific use case has been moved here . My original..

Why do we need tuples in Python (or any immutable data type)?

http://stackoverflow.com/questions/2174124/why-do-we-need-tuples-in-python-or-any-immutable-data-type

languages. in Python in particular only immutables can be hashable and therefore members of sets or keys in dictionaries . Again..

Python: removing duplicates from a list of lists

http://stackoverflow.com/questions/2213923/python-removing-duplicates-from-a-list-of-lists

lists I could used set . But unfortunate that list is not hashable and can't make set of lists. Only of tuples. So I can turn all..

Why is ''>0 True in Python? [duplicate]

http://stackoverflow.com/questions/2384078/why-is-0-true-in-python

getting only unique items in any list even one with non hashable items in O N log N worst case time Over the years this pragmatical..

what would be a frozen dict?

http://stackoverflow.com/questions/2703599/what-would-be-a-frozen-dict

could be a tuple. What would be a frozen dict An immutable hashable dict. I guess it could be something like collections.namedtuple.. unknown arguments. The most common solution to store a hashable equivalent of a dict where the values are hashable is something.. store a hashable equivalent of a dict where the values are hashable is something like tuple sorted kwargs.iteritems . This depends..

In Python, when to use a Dictionary, List or Set?

http://stackoverflow.com/questions/3489071/in-python-when-to-use-a-dictionary-list-or-set

different use cases obviously. set requires items to be hashable list doesn't if you have non hashable items therefore you cannot.. requires items to be hashable list doesn't if you have non hashable items therefore you cannot use set and must instead use list.. length in the average and worst cases. So if you have hashable items don't care either way about order or duplicates and want..

check if all elements in a list are identical

http://stackoverflow.com/questions/3844801/check-if-all-elements-in-a-list-are-identical

the 3 versions are that In checkEqual2 the content must be hashable. checkEqual1 and checkEqual2 can use any iterators but checkEqual3..

How to improve performance of this code?

http://stackoverflow.com/questions/4295799/how-to-improve-performance-of-this-code

much more efficient than for lists. However lists aren't hashable items so you will have to change your configurations into tuples..

Python - anyone have a memoizing decorator that can handle unhashable arguments?

http://stackoverflow.com/questions/4669391/python-anyone-have-a-memoizing-decorator-that-can-handle-unhashable-arguments

anyone have a memoizing decorator that can handle unhashable arguments I've been using the following memoizing decorator.. based cache means that all of my arguments must be hashable. Does anyone have an implementation or a tweak to this one that.. an implementation or a tweak to this one that allows for unhashable arguments e.g. dictionaries I know that the lack of a hash value..

How to efficiently compare two unordered lists (not sets) in Python?

http://stackoverflow.com/questions/7828867/how-to-efficiently-compare-two-unordered-lists-not-sets-in-python

O n The Counter method is best if your objects are hashable def compare s t return Counter s Counter t O n log n The sorted.. return sorted s sorted t O n n If the objects are neither hashable nor orderable you can use equality def compare s t t list t..