I have a List like this:

```
oldL = [
    {"id":1, "name":"aaa"},
    {"id":2, "name":"bbb"},
    {"id":3, "name":"ccc"},
]

```

and I want to convert to this:

```
newL = [
    {"id":1, "name":"aaa", "age":16},
    {"id":2, "name":"bbb", "age":16},
    {"id":3, "name":"ccc", "age":16}
]

```

By using "for structure" like this:

```
li = []
for sd in oldL:
    sd.update({"age":16})
    li.append(sd)
print(li)

```

I can get the right result, **But I want to use the Comprehensions, How to get it? Thanks a lot.**

I had test the case:

```
newL=[ sd.update({"age": 16}) for sd in oldL]

```

but I got `[None, None, None]`, because the return value of update() is None.

If I test the case like this:

```
detailL =[ (sd.update({"age": 16}), sd) for sd in schedule_detailL]

```

the result is :

```
[(None, {'id': 1, 'name': 'aaa', 'schedule_id': 1}), (None, {'id': 2, 'name': 'bbb', 'schedule_id': 1}), (None, {'id': 3, 'name': 'ccc', 'schedule_id': 1})]

```