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
4
votes
2 answers
Why does Python unpacking operator work with unordered collections
The Python 3 tutorial about the unpacking operator (*) generically speaks of a "list or tuple," while the error message for improper use says that a "sequence" is needed:
Python 3.5.1 (v3.5.1:37a07cee5969, Dec 6 2015, 01:38:48) [MSC v.1900 32 bit…
brianpck
- 8,084
- 1
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- 33
4
votes
2 answers
python: calling constructor from dictionary?
I'm not quite sure of the terminology here so please bear with me....
Let's say I have a constructor call like this:
machineSpecificEnvironment = Environment(
TI_C28_ROOT = 'C:/appl/ti/ccs/4.1.1/ccsv4/tools/compiler/c2000',
JSDB =…
Jason S
- 184,598
- 164
- 608
- 970
4
votes
1 answer
Pass in argument to function by name dynamically
Is it possible to dynamically set the name of an argument being passed into a function?
like this:
def func(one=None, two=None, three=None, four=None):
...
params = ("one","two","three","four",)
for var in params:
tmp = func(var=value)
Jeremy
- 1,717
- 5
- 30
- 49
4
votes
2 answers
Python style for line length and format when unpacking many return values
Suppose that function some_descriptively_named_function returns a 4-tuple of 4 return parameters. I want to call some_descriptively_named_function, adhere to the 80-character line length limit, and unpack all 4 outputs each into a…
ely
- 74,674
- 34
- 147
- 228
3
votes
4 answers
Unpack without using * (asterisk)
If I want to keep things functional, and do not want to use * in the middle, then what is the equivalent substitute function?
for example,
import operator as op
print(op.eq(*map(str.upper, ['a', 'A'])))
how do I avoid using * here?
I created a…
apostofes
- 2,959
- 5
- 16
- 31
3
votes
1 answer
Can I unpack/destructure a typing.NamedTuple?
This is a simple question so I'm surprised that I can't find it asked on SO (apologies if I've missed it), and it always pops into my mind as I contemplate a refactor to replace a tuple by a NamedTuple.
Can I unpack a typing.NamedTuple as arguments…
Cai
- 1,726
- 2
- 15
- 24
3
votes
3 answers
Unpacking a class
I'd like to make a class that unpacks it's objects like a dictionary.
For example, with a dictionary you can do this
foo = {
"a" : 1
"b" : 2
}
def bar(a,b):
return a + b
bar(**foo)
outputs 3
And I'd like to be able to do this
class…
financial_physician
- 1,672
- 1
- 14
- 34
3
votes
3 answers
Object unpacking assignment operation?
Is there anything like this in JavaScript? Basically, I'm looking for something along these lines:
let obj_a = {test: "one", property: "two"};
let obj_b = {test: "1", other: "three"};
let obj_b ...= obj_a; // would be the equivalent of obj_b =…
Maurdekye
- 3,597
- 5
- 26
- 43
3
votes
1 answer
How to disable pylint report of "E1120: No value for argument if" when passing a *args as list
I have the following code section that triggers Pylint error "E1120: No value for argument if".
framework/packages/create_network.py:79:21: E1120: No value for argument 'bridge1' in function call (no-value-for-parameter)
Is there a flag for Pylint…
RaamEE
- 3,017
- 4
- 33
- 53
3
votes
4 answers
How to create a function that takes dictionary inputs?
I am using a module for a project, I have to pass a function to the module and the model does something like:
class module:
def __init__(self, function, dictionary):
# dictionary is {'x':2, 'y':4, 'z':23}
function(**dictionary)
And…
ѕняєє ѕιиgнι
- 823
- 3
- 11
- 32
3
votes
1 answer
Replacing the parameters of a function with a vector
In Scala, if I have a function f(X, Y, Z) is it possible to pass a variable W that will represent (X, Y, Z) so I can use f(W) instead of f(X,Y,Z)? If so, how can this be done?
Jose Cabrera Zuniga
- 2,348
- 3
- 31
- 56
3
votes
1 answer
Why does set().union(*list1) gives me the union of two list inside a list?
I am doing an assignment, which requires me to do a code walkthrough. I would like to have a brief description on how set().union(*list1) works so i can answer during my walkthrough.
list1 = [[1,2,3],[1,2,3,5,8]]
x =…
ProgrammingWarrior
- 57
- 5
3
votes
1 answer
How to unpack parameters in Python?
Is it possible to unpack parameters in python like in javascript?
def foo([ arg ]):
pass
foo([ 42 ])
Monsieur Pierre Doune
- 687
- 8
- 29
3
votes
2 answers
unpacking multiple arguments from a list in a for loop
I have two lists.
d1 = ["'02/01/2018'", "'01/01/2018'", "'12/01/2017'"]
d2 = ["'02/28/2018'", "'01/31/2018'", "'12/31/2017'"]
I am trying to get these values to be unpacked in a for loop.
for i,y in d1,d2:
i,y = Startdate, Enddate
I realize…
Rob Friedman
- 95
- 2
- 8
3
votes
1 answer
What data model methods implement argument keyword unpacking?
I have a class that I would like to be able to unpack into an argument list using the *args and **kwargs syntax.
class MyFoo:
x = 1
y = 2 # unpack x and y
z = 3 # do not unpack z
def bar(x, y):
print(x, y)
def baz(a, b=2, x=100,…
AJMansfield
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