Question

I’m having a python list preinitialized like this:
eventarray=[None]*10000

Is there any other way to preinitialize this list,so that 10000 can be a variable to be changed from different functions inside,without changing the data in the list.

Note:preinitialisation is done for inserting value on a particular offset of list.

Answer 1

From what I can infer from your question, you want to create a list with global scope, with its length determined at runtime.

Edit: The following code now extends the list as necessary each time my_list_creator is accessed:

foo = []

def my_list_creator(n):
    '''Makes the nth value in a list n. If the list is not
    long enough, it extends it, initialised with None.
    '''
    global foo

    if len(foo) < n:
        foo.extend([None] * (n - len(foo)))

    foo[n-1] = n

def access_a_global():
    print foo

def another_func():
    my_list_creator(10)
    access_a_global()
    my_list_creator(20)        
    access_a_global()

another_func()

foo is global in scope, but is initialised as necessary.