Is there any reason to do anything more complicated than one of these two lines when you want to clear a list in Python?
old_list =  old_list = list()
The reason I ask is that I just saw this in some running code:
del old_list[ 0:len(old_list) ]
Clearing a list in place will affect all other references of the same list.
For example, this method doesn't affect other references:
>>> a = [1, 2, 3] >>> b = a >>> a =  >>> print(a)  >>> print(b) [1, 2, 3]
But this one does:
>>> a = [1, 2, 3] >>> b = a >>> del a[:] # equivalent to del a[0:len(a)] >>> print(a)  >>> print(b)  >>> a is b True
You could also do:
>>> a[:] = 
There is a very simple way to clear a python list. Use del list_name[:].
>>> a = [1, 2, 3] >>> b = a >>> del a[:] >>> print a, b