Given two numpy arrays, how to split one into an array of lists based on the second Question: I have two numpy arrays: one containing arbitrary values, and one containing integers larger than 1. The sum of the integers is equal to the length of the first array. Sample: values = np.array(["a", "b", "c", "d", …
How can I make this Indexing algorithm more efficient? Question: I’ve got a Dataframe (deriving from a csv file with various columns) with 172033 rows. I’ve created a custom indexing function that blocks pairs of records that haven’t got similar ‘name’ attributes. The problem resides in the efficiency of the algorithm. Just to get to …
Why is b.pop(0) over 200 times slower than del b[0] for bytearray? Question: Letting them compete three times (a million pops/dels each time): from timeit import timeit for _ in range(3): t1 = timeit(‘b.pop(0)’, ‘b = bytearray(1000000)’) t2 = timeit(‘del b[0]’, ‘b = bytearray(1000000)’) print(t1 / t2) Time ratios (Try it online!): 274.6037053753368 219.38099365582403 252.08691226683823 …
Is using else faster than returning value right away? Question: Which of the following is faster? 1. def is_even(num: int): if num%2==0: return True else: return False def is_even(num: int): if num%2==0: return True return False I know you can technically do this: def is_even(num: int): return n%2==0 But for the sake of the question, …
How can i make this python code quicklier? Question: How can i make this code more quicklier? def add_may_go(x,y): counter = 0 for i in range(-2,3): cur_y = y + i if cur_y < 0 or cur_y >= board_order: continue for j in range(-2,3): cur_x = x+j if (i == 0 and j == 0) …
I don't understand why is this for loop so fast? Question: Today I was solving Project Euler’s problem #43 Problem and I ran into a somewhat interesting problem. I don’t understand why is my code so fast? from itertools import permutations def main(): numbers1_9 = [0,1,2,3,4,5,6,7,8,9] list_of_all_permutations = list(permutations(numbers1_9, 10)) length_of_my_list = len(list_of_all_permutations) number_of_times_it_ran=0 result …
Multithreaded python program performance loss after laptop upgrade Question: I have been having this weird issue where my new laptop handles an albeit computationally intensive program I wrote worse than my last one. The code is a python program I wrote that measures errors in a numerical model for a large set of data. It …
Same python commands take different time if called in different ways Question: I have some data (bytes) represending a png image that come over a pyzmq socket from an executable running in the background. I transform these to a numpy array using the following command decoded = np.asarray(im.open(io.BytesIO(data))) When I do this from the command …
Simulation of Markov chain slower than in Matlab Question: I run the same test code in Python+Numpy and in Matlab and see that the Matlab code is faster by an order of magnitude. I want to know what is the bottleneck of the Python code and how to speed it up. I run the following …
I am using a large module in many of my files that takes some time to import. Will importing it in every file waste time? Question: I have a module that takes a while to import, let’s call it big_module. This module creates several variables that I need in my other files. I use this …
