All Questions
Tagged with pass-by-reference python
289 questions
0
votes
0
answers
24
views
SWIG function returning reference
I want to run SWIG on the following C++ structure :
struct TestAlias
{
TestAlias(double a1, double a2, double a3) : angle1(a1), angle2(a2), angle3(a3) {}
...
- 83
0
votes
1
answer
78
views
Is it possible to pass a python list slice as reference? [duplicate]
I was playing with python to try to reduce memory usage using various methods. One question that arose is if there's a way to pass a list slice as reference to the original list.
The reason was the ...
- 283
0
votes
0
answers
703
views
Append DataFrame Rows In-Place Within a Function in Pandas: Elegant Solutions?
I am looking for a clear and efficient way to append rows to a DataFrame in-place within a function in pandas. Here's what I got so far:
pd.concat Approach (Not In-Place):
def append_rows_concat(df, ...
-1
votes
2
answers
96
views
List modification in recursive function calls
I have two simple recursive functions in Python as follows:
def test_list(outcome=[1]):
outcome += [2*outcome[-1]]
print(outcome)
if outcome[-1] < 8:
test_list(outcome)
...
- 11
1
vote
2
answers
77
views
Combining two lists into a list of dictionaries and all the values are the same
I have two lists I want to combine :
old = ['aaa', 'bbb', 'ccc']
new = ['AAA', 'BBB', 'CCC']
and I want to make a list of dict as shown below :
myList = [{'lama': 'aaa', 'baru': 'AAA'}, {'lama': 'bbb'...
- 43
0
votes
2
answers
81
views
How do I call multiple python functions by reference to operate on a variable so that I can change the sequence of function calls easily?
I want to create a 'function pipeline', like a factory.
Let's say I have the following functions:
def func1(var):
var = # do something with var
return var
def func2(var):
var = # do ...
- 1,768
-1
votes
2
answers
581
views
Why did this python list appear to get passed "by value"? [duplicate]
I defined the following function:
def myFunction(a):
print(f'In function, initial a = {a}, {id(a)}, {type(a)}')
a = a*10
print(f'In function, final a = {a}, {id(a)}, {type(a)}')
return a
When ...
- 1
0
votes
1
answer
39
views
Some Issues in Tree Iteration in Python while the Tree Can be Dynamically Generated on the Fly
I am writing the following functionality. A root nodes is given with 2 set of indices (_indices_lhs and _indices_rhs), and fore every index that apperas in both the left hand side and right hand side ...
- 181
0
votes
1
answer
425
views
Sort Dictionary by Reference? (Python 3.10)
I'm attempting to sort a dictionary in Python in ascending key order. I'm trying to do this inside of a function, with the dictionary being supplied as an argument.
I understand that there are mutable ...
- 675
0
votes
1
answer
43
views
How to call the argument name of a constructor inside a new function?
A DecisionTreeRegressor has the callable arguments of max_depth, min_samples_split, and so on. I want to create a function that chooses which argument (feature of the tree) to call. An example:
import ...
- 11
0
votes
2
answers
401
views
Value of variable is not updated after passing it as a parameter into method in Python [duplicate]
Scenario:
I declared a variable with value 0 in the method;
Then I passed this variable as a parameter to another method which is called from first method.
Nested method incremented value of the ...
0
votes
0
answers
31
views
Deep reference ..? | Intertools.product() [duplicate]
The following (pseudo) code should insert only one ZERO per pair
from itertools import product
In [321]:
for p in product([[1],[2]],[[4],[5]]):
p[0].insert(0,0)
print(p)
Out [321]
([0, ...
- 7,486
0
votes
1
answer
30
views
Linked list implementation in python issue
I have been trying to implement a linked-list in python.Any call of a variable inside a function in Python is by default call by reference.I have this code:
For the list_node:
class list_node:
...
- 137
2
votes
1
answer
438
views
How do you pass in another object of the same type as a method parameter in python?
I am creating a class in python to represent a three-dimensional point (I know there are libraries to do this, it's more of an exercise in classes). One type of method I wish to have is one which can ...
-2
votes
1
answer
38
views
Why copying lists (which are called by functions) with [:] doesn't work?
I have two lists like:
prelist = [0, 0, 0, 0, 0]
postlist = [50.0, 25.0, 12.5, 6.25, 3.125]
I tried copying the list like so:
prelist = postlist[:]
but the surrounding code didn't work.
When I copy ...
