What is the fastest way to check if a value exists in a very large list? Answer Clearest and fastest way to do it. You can also consider using a set, but constructing that set from your list may take more time than faster membership testing will save. The only way to be certain is to benchmark well. (this also
Tag: performance
[] and {} vs list() and dict(), which is better? [closed]
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Efficiently detect sign-changes in python
I want to do exactly what this guy did: Python – count sign changes However I need to optimize it to run super fast. In brief I want to take a time series and tell every time it crosses crosses zero (changes sign). I want to record the time in between zero crossings. Since this is real data (32 bit
Get difference between two lists with Unique Entries
I have two lists in Python: Assuming the elements in each list are unique, I want to create a third list with items from the first list which are not in the second list: Are there any fast ways without cycles and checking? Answer To get elements which are in temp1 but not in temp2 (assuming uniqueness of the elements in
Numpy and line intersections
How would I use numpy to calculate the intersection between two line segments? In the code I have segment1 = ((x1,y1),(x2,y2)) and segment2 = ((x1,y1),(x2,y2)). Note segment1 does not equal segment2. So in my code I’ve also been calculating the slope and y-intercept, it would be nice if that could be avoided but I don’t know of a way how.
Python string join performance
There are a lot of articles around the web concerning Python performance. The first thing you read is concatenating strings should not be done using ‘+’; avoid s1 + s2 + s3, and instead use str.join I tried the following: concatenating two strings as part of a directory path: three approaches: ‘+’ which I should not do str.join os.path.join Here