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 th…
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 …
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 numbe…
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 …
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 AN…
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 lis…
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