我如何设置枚举的增加，取决于条件？

Question

I have got the following loop^

i = 0
for var in vars:
    if var[ "ID" ] != 0 and var[ "ID" ] & 1:
        print i, var[ "ID" ]
        i += 1      

Can I use enumerate for this loop instead of counter i ? How i can set the increasing of enumerate, that depends on this condition: if var[ "ID" ] != 0 and var[ "ID" ] & 1:

Answer 1

You may use filter :

>>> vs = [{'ID': 1}, {'ID': 4}]
>>> for i, v in enumerate(filter(lambda x: x['ID'] & 1, vs)):
...     print i, v
...
0 {'ID': 1}

Answer 2

No, I don't think you can use enumerate to simplify this code (not without thinning vars first, so that enumerate would only apply to elements that match the condition).

To be honest, I think the code is pretty straightforward as it is.