How to remove the first Item from a list

Question

I have the list  0  1  2  3  4  I d like to make it into  1  2  3  4   How do I go about this

User · Accepted Answer

You can find a short collection of useful list functions here.

list.pop(index)

>>> l = ['a', 'b', 'c', 'd']
>>> l.pop(0)
'a'
>>> l
['b', 'c', 'd']
>>>

del list[index]

>>> l = ['a', 'b', 'c', 'd']
>>> del l[0]
>>> l
['b', 'c', 'd']
>>>

These both modify your original list.

Others have suggested using slicing:

Copies the list
Can return a subset

Also, if you are performing many pop(0), you should look at collections.deque

from collections import deque
>>> l = deque(['a', 'b', 'c', 'd'])
>>> l.popleft()
'a'
>>> l
deque(['b', 'c', 'd'])

Provides higher performance popping from left end of the list

User · Answer

You can also use list remove a 0   to pop out the first element in the list    gt  gt  gt  gt  a  1 2 3 4 5   gt  gt  gt  gt  a remove a 0    gt  gt  gt  gt  print a  gt  gt  gt  gt   2 3 4 5

User · Answer

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

User · Answer

With list slicing  see the Python tutorial about lists for more details    gt  gt  gt  l    0  1  2  3  4   gt  gt  gt  l 1    1  2  3  4

User · Answer

If you are working with numpy you need to use the delete method   import numpy as np  a   np array  1  2  3  4  5    a   np delete a  0   print a     2 3 4 5

User · Answer

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

User · Answer

gt  gt  gt  x    0  1  2  3  4   gt  gt  gt  x pop 0  0   More on this here

User · Answer

Slicing   x    0 1 2 3 4  x   x 1     Which would actually return a subset of the original but not modify it

User · Answer

Then just delete it   x    0  1  2  3  4  del x 0  print x    1  2  3  4

User · Answer

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

[python] How to remove the first Item from a list?

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