pythonarrayslist

Pop multiple items from the beginning and end of a list


Suppose I have a list of items like this:

mylist=['a','b','c','d','e','f','g','h','i']

I want to pop two items from the left (i.e. a and b) and two items from the right (i.e. h,i). I want the most concise an clean way to do this. I could do it this way myself:

for x in range(2):
    mylist.pop()
    mylist.pop(0)

Any other alternatives?


Solution

  • From a performance point of view:

    Code

    iterations = 1000000
    print timeit.timeit('''mylist=range(9)\nfor _ in range(2): mylist.pop(0); mylist.pop()''', number=iterations)/iterations
    print timeit.timeit('''mylist=range(9)\nmylist = mylist[2:-2]''', number=iterations)/iterations
    print timeit.timeit('''mylist=range(9)\ndel mylist[:2];del mylist[-2:]''', number=iterations)/iterations
    

    output

    1.07710313797e-06

    3.44465017319e-07

    3.49956989288e-07