Insert at first position of a list in Python
From the documentation:
list.insert(i, x)
Insert an item at a given position. The first argument is the index of the element before which to insert, soa.insert(0, x)
inserts at the front of the list, anda.insert(len(a),x)
is equivalent toa.append(x)
http://docs.python.org/2/tutorial/datastructures.html#more-on-lists
Use insert
:
In [1]: ls = [1,2,3]
In [2]: ls.insert(0, "new")
In [3]: ls
Out[3]: ['new', 1, 2, 3]