[EMAIL PROTECTED] wrote:
> # I have a list of names:
> names = ['clark', 'super', 'peter', 'spider', 'bruce', 'bat']
>
> # and another set of names that I want to insert into
> # the names list at some indexed locations:
> surnames = { 1: 'kent', 3:'parker', 5:'wayne' }
>
> # The thing I couldn't figure out is, after I insert a
> # surname the rest of the indices are not valid.
> # That is, the following won't work:
> for i, x in surnames.iteritems():
> names.insert(i,surnames[i])
This seems to work (tested only with what you see below)::
>>> names = ['clark', 'super', 'peter', 'spider', 'bruce', 'bat']
>>> surnames = {1:'kent', 3:'parker', 5:'wayne'}
>>> for index in sorted(surnames, reverse=True):
... names.insert(index, surnames[index])
...
>>> names
['clark', 'kent', 'super', 'peter', 'parker', 'spider', 'bruce',
'wayne', 'bat']
I just did the inserts from right to left, that is, starting at the end.
That way, after an insert, I don't have to adjust any indices.
You may also find that if you do a lot of inserts into the list, it may
be more efficient to create a new list, e.g.::
>>> names = ['clark', 'super', 'peter', 'spider', 'bruce', 'bat']
>>> surnames = {1:'kent', 3:'parker', 5:'wayne'}
>>> new_names = []
>>> for i, name in enumerate(names):
... if i in surnames:
... new_names.append(surnames[i])
... new_names.append(name)
...
>>> new_names
['clark', 'kent', 'super', 'peter', 'parker', 'spider', 'bruce',
'wayne', 'bat']
STeVe
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