All Questions
380 questions
0
votes
3
answers
100
views
Accessing a class member inside another another class from a Python Lambda expression
I cannot understand why I cannot reference the integer member of the nested class in the lambda. The following code demonstrates the failure. The same reference is used in the print prior to the ...
3
votes
2
answers
125
views
How to make a `functools.reduce` implementation that looks similarly as `Reduce` in R?
Here is an R example of using Reduce
x <- c(1, 2, 2, 4, 10, 5, 5, 7)
Reduce(\(a, b) if (tail(a, 1) != b) c(a, b) else a, x) # equivalent to `rle(x)$values`
The code above is to sort out the ...
- 104k
0
votes
0
answers
73
views
Skewness and kurtosis for image processing
While running python map reducing code to calculate skewness and kurtosis values i am unable to get output:
Code
import os
from mrjob.job import MRJob
from scipy.stats import skew, kurtosis
import ...
-1
votes
1
answer
79
views
Applying a function to all elements of a tree in Python
There is a tree-like data structure, the nodes of which contain scalar values (integers), lists and dictionaries, np.array.
I need to write a function (in Python) that applies an aggregation function ...
- 7
0
votes
1
answer
167
views
Most Pythonic way to handle exception caused by functools.reduce when the iterable yields no elements?
Python's functools.reduce throws an exception when the iterable passed to it yields no elements.
Here's how I currently use it:
some_list = [] # empty list should be permissible
functools.reduce(
...
- 17.9k
2
votes
0
answers
114
views
MapReduce Troubleshoot with python script as mapper and reducer using hadoop-streaming-3.3.6.jar
core-site.xml config :
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://Master:9000</value>
</property>
</...
1
vote
3
answers
109
views
Given a list of lists of two timestamps, how to check if the index of a dataframe is inside those datetime range?
I have a list of lists of two elements with type pd.Timestamp, e.g.:
intervals = [
[pd.Timestamp('2023-01-01 02:00:00'), pd.Timestamp('2023-01-01 03:00:00')],
[pd.Timestamp('2023-01-01 05:00:...
- 77
0
votes
1
answer
64
views
How does reduceByKey() in pyspark knows which column is key and which one is value?
I'm a newbie to Pyspark and going through this.
How does reduceByKey() know whether it should consider the first column as and second as value or vice-versa.
I don't see any column name or index ...
- 5,230
-1
votes
1
answer
117
views
naive cuda kernel for ReduceL2 operator
I am trying to implement a cuda kernel for the operator ReduceL2 for educational purpose. For example, I have a 3-d tensor with shape 400*500*256 and it should be 'l2'-reduced along the first and ...
- 309
0
votes
2
answers
157
views
Multiprocessed reduce function hangs when task queue size of above 1200 elements in Python
the program works fine untill the size of the to_sum list reaches about 1150. Afterwards, the processes will hang at the first point where task_queue = result_queue. They will successfully fill the ...
- 103
0
votes
1
answer
93
views
How do I reduce a list of tuples into one output?
I just completed a mapper and groupby script. Running it in my terminal gives me a list of tuples:
a [('1', '0', '0'), ('1', '1', '1')]
b [('1', '0', '0')]
e [('1', '0', '0'), ('1', '0', '1')]
f [('1',...
- 158
0
votes
1
answer
65
views
How to reduce the length of this code written with python.turtle?
I need help reducing the total length or lines of this code written with python.turtle. I need to have the same output and just reduce the length of the lines if possible using other functions! Here ...
- 11
0
votes
1
answer
83
views
Understanding Unusual Behavior in Python's functools.reduce() Function with Custom Reducer Function
I've been working on a Python project that requires the use of the functools.reduce() function. I came across an unusual behavior when using a custom reducer function, and I am unable to figure out ...
user21429639
3
votes
1
answer
169
views
Error: 'int' object is not subscriptable - when using lambda in reduce function
When running the following code, I get the following Error:
Traceback (most recent call last):
File "/Users/crosseyedbum/Documents/Visual Studio Code/Fundamentals of Python_5.py", line 127,...
1
vote
1
answer
117
views
python reduce return function reference and not the value of the function
Learning Python. I was learning reduce() and was playing with the initialization parameter. The code simply outputs a SHA256 hash of a list of strings. At first I used a for loop to generate the ...
