I want to append each element of [1,2] to [[1], [2], [3]] and as a consequence, the final array that I want is [[1,1], [1,2], [2,1], [2,2], [3,1], [3,2]] But my code has a mistake I couldn’t recognize it yet, and the result of the python code below is [[1, 1, 2], [1, 1, 2], [2, 1, 2], [2, 1,
Tag: list
Fast shaping of multiprocessing return values in Python
I have a function with list valued return values that I’m multiprocessing in Python and I need to concatenate them to 1D lists at the end. The following is a sample code for demonstration: The output for illustration is: The problem is that the list L that I’m processing is pretty huge and that the concatenations at the end take
append string to list/string returns ‘None’ or ‘AttributeError: ‘str’ object has no attribute ‘append” in python
I’m trying to add 1 word/string to the back of the sentence ‘Afterall , what affects one family ‘. Using the append method, it either returns ‘None’ if I append directly to the list or it will return an error ‘AttributeError’ if I append to the string. May I know how do I add the word/string to the back of
How to replace equal consecutive numbers in a list to nan?
I’m trying to replace equal consecutive numbers in a list to nan. I having problems to replace all values when there is a odd number of equal consecutive numbers. This is my code, very simple: Another question, if I want to replace only those values that repeated more than 3 times, for example the numbers 1 or 2 that are
Moving specific number (without sort) to the left of list
I want to just move the zero’s to left and don’t want to sort the list. For example, if my list is like: Here’s the output which I desire after moving all the Zero’s to left: Here’s the code I tried: This code gives me output as: But my desired output is: Answer
Looping through multiple columns in a table in Python
I’m trying to loop through a table that contains covid-19 data. My table has 4 columns: month, day, location, and cases. The values of each column in the table is stored in its own list, so each list has the same length. (Ie. there is a month list, day list, location list, and cases list). There are 12 months, with
Error with using length function; output will not be anything other than one
I have multiple csv files I’ve uploaded into both google colab and jupyter notebook. I can successfully print certain lines of my file. The file contains rows of strings. When I open the file it opens the number application of my MacBook. Anyways, for some reason whenever I try to print the length of ANY line in my file, python
Replacing list comprehensions with pandas and numpy Python
The function below uses slices to get the maximum value between 2 indexes at once. So it gets the maximum value between 0 and 10 and then 10 and 12 and such. The function is derived from the answer to this post post. Is there a way I could could replace the list comprehensions in the form of a pandas
Creating list of dictionaries from a dictionary using list comprehension
I have a dictionary of the format: And I’m trying to create a list of dictionaries that separate the values, i.e., the result should be: Is there a way I can do this with a one-line list comprehension? What I have tried so far: And my code using a normal “for” loop: Answer Here’s a list comprehension + dictionary comprehension
how to convert 1d list to 2d list with some some number of columns?
I want to convert a 1d list to 2d in python. I found a way to do it with NumPy, but it gives the following error when the length of the list is not divisible by the number of columns: ValueError: cannot reshape array of size 9 into shape (4) In the case that the length is not divisible, I