You can also use list.remove(a[0])
to pop
out the first element in the list.
>>>> a=[1,2,3,4,5]
>>>> a.remove(a[0])
>>>> print a
>>>> [2,3,4,5]
Then just delete it:
x = [0, 1, 2, 3, 4]
del x[0]
print x
# [1, 2, 3, 4]
You can use list.reverse()
to reverse the list, then list.pop()
to remove the last element, for example:
l = [0, 1, 2, 3, 4]
l.reverse()
print l
[4, 3, 2, 1, 0]
l.pop()
0
l.pop()
1
l.pop()
2
l.pop()
3
l.pop()
4
There is a data structure called deque
or double ended queue which is faster and efficient than a list. You can use your list and convert it to deque and do the required transformations in it. You can also convert the deque back to list.
import collections
mylist = [0, 1, 2, 3, 4]
#make a deque from your list
de = collections.deque(mylist)
#you can remove from a deque from either left side or right side
de.popleft()
print(de)
#you can covert the deque back to list
mylist = list(de)
print(mylist)
Deque also provides very useful functions like inserting elements to either side of the list or to any specific index. You can also rotate or reverse a deque. Give it a try!
With list slicing, see the Python tutorial about lists for more details:
>>> l = [0, 1, 2, 3, 4]
>>> l[1:]
[1, 2, 3, 4]
you would just do this
l = [0, 1, 2, 3, 4]
l.pop(0)
or l = l[1:]
Pros and Cons
Using pop you can retrieve the value
say x = l.pop(0)
x
would be 0
>>> x = [0, 1, 2, 3, 4]
>>> x.pop(0)
0
Slicing:
x = [0,1,2,3,4]
x = x[1:]
Which would actually return a subset of the original but not modify it.
Source: Stackoverflow.com