Use this tag for questions related with argument unpacking, a technique that allows Arrays and Traversable objects to be extracted/unpacked into argument lists/sequences.
argument-unpacking is usually found in PHP, Python and Go.
Questions tagged [argument-unpacking]
144 questions
1
vote
1 answer
Lua flexible function argument unpacking in local function
I am working on command handler that needs to work in two environments. Below is a a small part of the function I am working on, which I think captures the problem. At least, I get the error message I need to adress.
In the live environment, a…
Fredrik Karlsson
- 485
- 8
- 21
1
vote
1 answer
pool.apply_async with multiple parameters
The below code should call two databases at the same time. I tried to do it with
ThreadPool but run into some difficulties. pool.apply_async doesn't seem to allow multiple parameters, so I put them into a tuple and then try to unpack them. Is this…
Nickpick
- 6,163
- 16
- 65
- 116
1
vote
2 answers
Javascript: argument unpacking in function.prototype.bind()?
The closest I've seen is this, but it doesn't really help me since I need to bind some parameters for later use with setInterval.
More specifically:
[in] var d = function(l, m) {
console.log(l);
console.log(m);
}
[in]…
13steinj
- 427
- 2
- 9
- 16
1
vote
1 answer
std::pair assignment with downcast
For timeouts in event reactors and proactors I use a priority queue that also allows O(log(n)) random access removes of events (when the event is signalled/completes rather than a timeout occurring). I store…
Display Name
- 2,323
- 1
- 26
- 45
1
vote
4 answers
Unpacking multiple variables in a for loop over a dictionary
Can someone please tell me why I am getting an unpacking error in the below code?
bucket = {
'a': 'Joe',
'b': 'Brooke',
'c': 'Scott',
'd': 'Sam',
}
for i, kv in enumerate(bucket):
k, v = kv
print i, k, v
tslaw04
- 21
- 1
- 3
1
vote
2 answers
Python: Unpack individual strings from tuple using Unpacking asterisk argument
In the following code, I am trying to create a new word by iterating over all words fed as arguments of varying length, string type. I read here * operator makes it non keyword optional arguments.
def gen_new_word(word1,*nwords):
new_word=''
t0=[i…
user2290820
- 2,709
- 5
- 34
- 62
1
vote
3 answers
What are the pitfalls of keyword argument unpacking of instance' __dict__?
I'm trying to make convenient passing some set of arguments to a number of functions (say 20).
Consider the following MWE (of course I don't really consider doing additions in such way):
def function(a, b):
return a + b
class summation:
…
Michael Pankov
- 3,581
- 2
- 23
- 31
0
votes
0 answers
Can I use an inspect.Signature instance as a signature for function that an ide will see?
Can I use an inspect.Signature instance as a signature for function that an ide will see?
I am asking because I want a way to requires specikic key value pairs, and a catch all type for unknown other keywords. Function signatures and kwargs let one…
spacether
- 2,136
- 1
- 21
- 28
0
votes
0 answers
Return a reference to unpacked dictionary in Python
There is a common way to pass arguments in Python like this:
def foo(a1, a2):
print(a1, a2)
def my_dict():
return {'a1': 4, 'a2':5}
foo(**my_dict())
...
4 5
But now I want to move the asterisks inside my_dict function:
def foo(a1,…
Ars ML
- 49
- 4
0
votes
0 answers
Two-column pandas dataframe unpacking into string variables of column names
I have a function that if you pass it some data identifier, it will return a pandas dataframe of that dataset. I've just added a new parameter that, when True, returns a second dataframe with metadata about the dataset. So the function can return…
Julia
- 1
- 1
0
votes
1 answer
ValueError: too many values to unpack (expected 5) in for loop in Pandas Dataframe
I have a huge dataframe that looks like
df = pd.DataFrame([
[1, "1/1/2023", 1, 3],
[1, "1/1/2023", 2, 2],
[1, "1/1/2023", 3, 1],
[1, "1/1/2023", 4, 4],
[2, "11/9/2022", 1, 2],
[2, "11/9/2022", 2, 3],
[2, "11/9/2022", 3,…
Nayr borcherds
- 395
- 1
- 6
0
votes
1 answer
print(*myVar) invalid syntax
Trying to print list items on individual lines as simply as possible following this:
https://www.geeksforgeeks.org/print-lists-in-python-4-different-ways/
>>> myVar = [1, 2, 3, 4, 5]
>>> print(*myVar)
File "", line 1
print(*myVar)
…
L0Lock
- 147
- 13
0
votes
1 answer
Python : * Operator in list comprehension
Evening all,
I have recently discover the * operator to unpack my list. I find it quite elegant but I am a bit struggling with it.
Please find below an example :
from matplotlib.pyplot import Line2D
COLOR_FCT = {
"a": ["blue", "Al", "-"],
"b":…
MatPl
- 45
- 4
0
votes
2 answers
How to unpack only values from nested dict in for loop
I have the following code
mydict = {
"key": {
"k1": "v1",
"k2": "v2",
}
}
for k, (v1, v2) in mydict.items():
v1 and v2 actaully equals to k1 and k2, is there a way to extract v1 and v2 with any unpacking syntax?
I tried to…
Paz
- 72
- 6
0
votes
2 answers
How to unpack a list of colons and NumPy Nones to index an array?
I am writing a program that will have an arbitrary number of : and None in arbitrary locations of an n-dimensional NumPy array. Therefore, I want a way to unpack these : and None axis operators into the [] that indexes an array and auto-populates…
ExactPlace441
- 23
- 5