In the CSV I’m reading from, there are multiple rows for each ID: I need to extract each such that I will have one file per ID, with the timestamp, name, and text in that file. For example, for ID 444, it will have 2 timestamps and 2 different texts in it, along with the name. I’m able to get
Tag: defaultdict
“RuntimeError: dictionary changed size during iteration” but it’s not changed in the loop
I’m solving this LeetCode problem and here’s my code: The line for c in adjacent throws “RuntimeError: dictionary changed size during iteration”, which I don’t understand. I’m not modifying adjacent in dfs(), am I? Answer The main Problem is when dfs method is called it uses this line This just returns the associated value if it exists in defaultdict, if
Nested `defaultdict of defaultdict of defaultdict` each with a backreference
Using tree = lambda: dedfaultdict(tree), I can replace the following code: with: What I actually want is for each dictionary node to have a backreference to its parent dictionary node. I can do this as follows: (proof that this works: link) So, given that I was able to use tree = lambda: defaultdict(tree) to replace node = node.setdefault(ch, {}) with
Python `collections.defaultdict` for the same class
I try to use a Trie data structure for some coding problem. For each node in a trie, you typically put a a list of reference of its children. So, I thought about using defaultdict to create a default empty trie node if some children does not exists in a lookup. However, I don’t know how to use defaultdict to