In python… I have a list of elements ‘my_list’, and a dictionary ‘my_dict’ where some keys match in ‘my_list’. I would like to search the dictionary and retrieve key/value pairs for the keys matching the ‘my_list’ elements. I tried this… But it doesn…
Tag: dictionary
Using @functools.lru_cache with dictionary arguments
I have a method that takes (among others) a dictionary as an argument. The method is parsing strings and the dictionary provides replacements for some substrings, so it doesn’t have to be mutable. This function is called quite often, and on redundant elements so I figured that caching it would improve i…
Detect last iteration over dictionary.iteritems() in python
Is there a simple way to detect the last iteration while iterating over a dictionary using iteritems()? Answer This is a special case of this broader question. My suggestion was to create an enumerate-like generator that returns -1 on the last item: Add gen = iter(gen) if you want it to handle sequences as we…
Recursive diff of two dictionaries (keys and values)?
So I have a python dictionary, call it d1, and a version of that dictionary at a later point in time, call it d2. I want to find all the changes between d1 and d2. In other words, everything that was added, removed or changed. The tricky bit is that the values can be ints, strings, lists, or dicts, so
[] and {} vs list() and dict(), which is better? [closed]
Closed. This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed 6 months ago. The community reviewed whether to reopen this question 6 months ago and left it closed: Or…
Letter Count Dictionary
My homework problem is to write a Python function called LetterCount() which takes a string as an argument and returns a dictionary of letter counts. However, my code includes white space and commas as a part of the dictionary which i don’t want. Can you please help me out. How do i remove the white spa…
Multi-level defaultdict with variable depth?
I have a large list like: I want to build a multi-level dict like: I know that if I use recursive defaultdict I can write table[A][B1][C1]=1, table[A][B2]=2, but this works only if I hardcode those insert statement. While parsing the list, I don’t how many []’s I need beforehand to call table[key1…
python: union keys from multiple dictionary?
I have 5 dictionaries and I want a union of their keys. I tried but it gave me an error Am I doing it wrong ? I using normal forloop but I wonder why the above code didn’t work. Answer Your solution works for the first two elements in the list, but then dict1 and dict2 got reduced into a
Convert [key1,val1,key2,val2] to a dict?
Let’s say I have a list a in Python whose entries conveniently map to a dictionary. Each even element represents the key to the dictionary, and the following odd element is the value for example, and I’d like to convert it to a dictionary b, where What is the syntactically cleanest way to accompli…
Comparing two dictionaries and checking how many (key, value) pairs are equal
I have two dictionaries, but for simplification, I will take these two: Now, I want to compare whether each key, value pair in x has the same corresponding value in y. So I wrote this: And it works since a tuple is returned and then compared for equality. My questions: Is this correct? Is there a better way t…