compare dictionary values

[rbt]

What's a good way to compare values in dictionaries? I want to find
values that have changed. I look for new keys by doing this:

new = [k for k in file_info_cur.i terkeys() if k not in
file_info_old.i terkeys()]
if new == []:
print new, "No new files."
else:
print new, "New file(s)!!!"

My key-values pairs are filepaths and their modify times. I want to
identify files that have been updated or added since the script last ran.

Thanks,
rbt

[Marc 'BlackJack' Rintsch]

Re: compare dictionary values

In <dp4124$pki$1@s olaris.cc.vt.ed u>, rbt wrote:
[color=blue]
> What's a good way to compare values in dictionaries?[/color]

Look them up and then compare!? ;-)
[color=blue]
> I want to find
> values that have changed. I look for new keys by doing this:
>
> new = [k for k in file_info_cur.i terkeys() if k not in
> file_info_old.i terkeys()]
> if new == []:
> print new, "No new files."
> else:
> print new, "New file(s)!!!"
>
> My key-values pairs are filepaths and their modify times. I want to
> identify files that have been updated or added since the script last ran.[/color]

This looks up each `key` from the `new` dictionary and compares the value
with the `old` one. If it's not equal or the key is not present in `old`
the key is appended to the `result`::

def new_and_changed _keys(old, new):
result = list()
for (key, value) in new:
try:
if old[key] != value:
result.append(k ey)
except KeyError:
result.append(k ey)
return result

Ciao,
Marc 'BlackJack' Rintsch

[rbt]

Re: compare dictionary values

Marc 'BlackJack' Rintsch wrote:[color=blue]
> In <dp4124$pki$1@s olaris.cc.vt.ed u>, rbt wrote:
>[color=green]
>> What's a good way to compare values in dictionaries?[/color]
>
> Look them up and then compare!? ;-)
>[color=green]
>> I want to find
>> values that have changed. I look for new keys by doing this:
>>
>> new = [k for k in file_info_cur.i terkeys() if k not in
>> file_info_old.i terkeys()]
>> if new == []:
>> print new, "No new files."
>> else:
>> print new, "New file(s)!!!"
>>
>> My key-values pairs are filepaths and their modify times. I want to
>> identify files that have been updated or added since the script last ran.[/color]
>
> This looks up each `key` from the `new` dictionary and compares the value
> with the `old` one. If it's not equal or the key is not present in `old`
> the key is appended to the `result`::
>
> def new_and_changed _keys(old, new):
> result = list()
> for (key, value) in new:
> try:
> if old[key] != value:
> result.append(k ey)
> except KeyError:
> result.append(k ey)
> return result
>
> Ciao,
> Marc 'BlackJack' Rintsch[/color]

Thanks Marc! I changed this line:

for (key, value) in new:

To this:

for (key, value) in new.iteritems() :

And, it works great. Thanks again.