Tag: Dictionaries & sets
-
Python set subset checks with <=: Spelling Bee word validation
Playing NYT Spelling Bee? Use Python to see if your word only uses allowed letters (ignoring length + center): With sets, <= checks “subset or equal”:
-
dict.fromkeys: Why a mutable default value gets shared
Create a Python dict with keys a/b/c and values 0: But don’t do this, since the value will be shared and mutable: {‘a’: [‘x’, ‘y’], ‘b’: [‘x’, ‘y’], ‘c’: [‘x’, ‘y’]} 🤯
-
Today’s lesson in “Python for non-programmers”: Dictionaries
My free, weekly “Python for non-programmers” course continues! Our topic for today: Dictionaries, the most important data structure in Python. If you’ve always wanted to program, then it’s still not to late to join us. The course is completely free of charge, and gives you free access to the course recordings (including previous lessons), forever…
-
Python dicts and memory usage
Bottom line: Use sys.getsizeof to measure a dict’s memory: an empty dictionary takes 240 bytes, because it starts with eight slots ready for key-value pairs. That number reflects the structure, not the data, so it stays at 240 no matter how big your values are, growing in jumps only as you add more pairs. Let’s…
-
Is it hashable? Fun and games with hashing in Python
One of the basic data types that Python developers learn to use, and to appreciate, is the dictionary, or “dict.” This is the Python term for what other languages call hashes, associative arrays, hashmaps, or hash tables. Dictionaries are pervasive in Python, both in the programs that we write, and in the implementation of the…
-
Creating Python dictionaries with “reduce”
In the last few installments (first, second, third, and fourth) of this series, we saw how “reduce” can be used to build up a scalar value (such as a number or string), or even a simple collection, such as a list (in Python) or an array (in Ruby). Â The jewel in the data-structure crown for…