Deborah Swanson wrote:
> I know it's your "ugly" answer, but can I ask what the '**' in
>
> fix = {label: max(values, key=len)}
> group[:] = [record._replace(**fix) for record in group]
>
> means?
d = {"a": 1, "b": 2}
f(**d)
is equivalent to
f(a=1, b=2)
so ** is a means to call a function with keyword arguments when you want to
decide about the *names* at runtime. Example:
>>> def f(a=1, b=2):
... print("a =", a)
... print("b =", b)
... print()
...
>>> for d in [{"a": 10}, {"b": 42}, {"a": 100, "b": 200}]:
... f(**d)
...
a = 10
b = 2
a = 1
b = 42
a = 100
b = 200
Starting from a namedtuple `record`
record._replace(Location="elswhere")
creates a new namedtuple with the Location attribute changed to "elsewhere",
and the slice [:] on the left causes all items in the `groups` list to be
replaced with new namedtuples,
group[:] = [record._replace(Location="elsewhere") for record in group]
is basically the same as
tmp = group.copy()
group.clear()
for record in tmp:
group.append(record_replace(Location="elsewhere"))
To support not just Location, but also Kind and Notes we need the double
asterisk.
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