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What does “hashable” mean in Python?
...y and a set member, because these data structures use the hash value internally.
All of Python’s immutable built-in objects are hashable, while no mutable containers (such as lists or dictionaries) are. Objects which are instances of user-defined classes are hashable by default; they all comp...
Get Folder Size from Windows Command Line
...shell -noprofile -command "ls -r|measure -sum Length"
1 I do have a partially-finished bignum library in batch files somewhere which at least gets arbitrary-precision integer addition right. I should really release it, I guess :-)
...
Permutations in JavaScript?
...
If you notice, the code actually splits the chars into an array prior to do any permutation, so you simply remove the join and split operation
var permArr = [],
usedChars = [];
function permute(input) {
var i, ch;
for (i = 0; i < inp...
In what areas might the use of F# be more appropriate than C#? [closed]
... sweet spot for the language within enterprise software, namely algorithmically complex analysis of large data sets. My experience has been a very positive one. In particular:
Units of measure The industry I work in is littered with units. The equations I implemented (often of a geometric nature) d...
How does deriving work in Haskell?
Algebraic Data Types (ADTs) in Haskell can automatically become instances of some typeclasse s (like Show , Eq ) by deriving from them.
...
Calling class staticmethod within the class body?
... def stat_func():
return 42
_ANS = stat_func.__func__() # call the staticmethod
def method(self):
ret = Klass.stat_func()
return ret
As an aside, though I suspected that a staticmethod object had some sort of attribute storing the original function, I had no ...
Scala type programming resources
...programming, the computation occurs at compile time. I will try to draw parallels between programming at the value-level and programming at the type-level.
Paradigms
There are two main paradigms in type-level programming: "object-oriented" and "functional". Most examples linked to from here follow...
Resolve build errors due to circular dependency amongst classes
...ember that the .cc and not the .h is the unit of compilation), you need to allocate space for object A. So, well, how much space then? Enough to store B! What's the size of B then? Enough to store A! Oops.
Clearly a circular reference that you must break.
You can break it by allowing the compiler ...
Flask-SQLAlchemy import/context issue
...:
# fields here
pass
And then in your application setup you can call init_app:
# apps.application.py
from flask import Flask
from apps.members.models import db
app = Flask(__name__)
# later on
db.init_app(app)
This way you can avoid cyclical imports.
This pattern does not necessitate ...
Stop pip from failing on single package when installing with requirements.txt
I am installing packages from requirements.txt
6 Answers
6
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