Python copy a list of lists
The difference between shallow and deep copying is only relevant for compound objects (objects that contain other objects, like lists or class instances):
list
Pythonic way to return list of every nth item in a larger list
Say we have a list of numbers from 0 to 1000. Is there a pythonic/efficient way to produce a list of the first and every subsequent 10th item, i.e. [0, 10, 20, 30, ... ]?
How to find the last occurrence of an item in a Python list
Say I have this list:
Calling filter returns
I am learning the concept of filters in Python. I am running a simple code like this. >>> def f(x): return x % 2 != 0 and x % 3 != 0 >>> filter(f, range(2, 25)) But instead of getting a list, I am getting some message like this. <filter object at 0x00FDC550> What does … Read more
How to get first element in a list of tuples?
I have a list like below where the first element is the id and the other is a string:
Is there a short contains function for lists?
I see people are using any to gather another list to see if an item exists in a list, but is there a quick way to just do something like this?
Pandas DataFrame to List of Dictionaries
I have the following DataFrame:
Why is [] faster than list()?
I recently compared the processing speeds of [] and list() and was surprised to discover that [] runs more than three times faster than list(). I ran the same test with {} and dict() and the results were practically identical: [] and {} both took around 0.128sec / million cycles, while list() and dict() took roughly 0.428sec / million cycles each.
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:
Create a list with initial capacity in Python
Code like this often happens: