Pairs from single list
Often enough, I’ve found the need to process a list by pairs. I was wondering which would be the pythonic and efficient way to do it, and found this on Google:
slice
Can I create a “view” on a Python list?
I have a large list l. I want to create a view from element 4 to 6. I can do it with sequence slice.
Selecting multiple slices from a numpy array at once
I’m looking for a way to select multiple slices from a numpy array at once. Say we have a 1D data array and want to extract three portions of it like below:
What is :: (double colon) in Python when subscripting sequences?
I know that I can use something like string[3:4] to get a substring in Python, but what does the 3 mean in somesequence[::3]?
Why are slice and range upper-bound exclusive?
Disclaimer: I am not asking if the upper-bound stopargument of slice()and range() is exclusive or how to use these functions.
Python pandas slice dataframe by multiple index ranges
What is the pythonic way to slice a dataframe by more index ranges (eg. by 10:12 and 25:28)?
How to get last items of a list in Python?
I need the last 9 numbers of a list and I’m sure there is a way to do it with slicing, but I can’t seem to get it. I can get the first 9 like this:
How to extract an arbitrary line of values from a numpy array?
I have a numpy array that contains some image data. I would like to plot the ‘profile’ of a transect drawn across the image. The simplest case is a profile running parallel to the edge of the image, so if the image array is imdat, then the profile at a selected point (r,c) is simply imdat[r] (horizontal) or imdat[:,c] (vertical).
Understanding string reversal via slicing
I was looking for a way to print a string backwards, and after a quick search on google, I found this method:
Pandas selecting by label sometimes return Series, sometimes returns DataFrame
In Pandas, when I select a label that only has one entry in the index I get back a Series, but when I select an entry that has more then one entry I get back a data frame.