|  | dict.update | | |
| | | Mike P |  |
|  Posted: Tue Sep 02, 2008 3:04 pm Post subject: dict.update |  |
Hi All,
I have two dictionaries e.g
dict1 = {123:3,234:5,456:3}
dict2 = {123:4,157:2,234:5,456:3,567:2}
I want to merge these two dictionaries together so i have a resultant
dictionary of:
dict3 = {123:[4,3],157:[2,0],234:[5,5],456:[3,3],567:[2,0]}
As later on i want to write a csv file that would have the form
id var1 var2
123 4 3
157 2 0
i looks like the dict.update looks almost there but i can't get it to
work properly, can anyone offer any advise? |
| |
| | | Diez B. Roggisch | |
| | Posted: Tue Sep 02, 2008 3:04 pm Post subject: Re: dict.update | |
Mike P schrieb:
| Quote: | Hi All,
I have two dictionaries e.g
dict1 = {123:3,234:5,456:3}
dict2 = {123:4,157:2,234:5,456:3,567:2}
I want to merge these two dictionaries together so i have a resultant
dictionary of:
dict3 = {123:[4,3],157:[2,0],234:[5,5],456:[3,3],567:[2,0]}
As later on i want to write a csv file that would have the form
id var1 var2
123 4 3
157 2 0
i looks like the dict.update looks almost there but i can't get it to
work properly, can anyone offer any advise?
|
res = {}
for d in dict1, dict2:
for key, value in d.iteritems():
res.setdefault(key, []).append(value)
Diez |
| |
| | | Tino Wildenhain | |
| | Posted: Tue Sep 02, 2008 3:04 pm Post subject: Re: dict.update | |
| |  | |
Mike P wrote:
| Quote: | Hi All,
I have two dictionaries e.g
dict1 = {123:3,234:5,456:3}
dict2 = {123:4,157:2,234:5,456:3,567:2}
I want to merge these two dictionaries together so i have a resultant
dictionary of:
dict3 = {123:[4,3],157:[2,0],234:[5,5],456:[3,3],567:[2,0]}
As later on i want to write a csv file that would have the form
id var1 var2
123 4 3
157 2 0
i looks like the dict.update looks almost there but i can't get it to
work properly, can anyone offer any advise?
|
result=dict((key,(dict1.get(key,None),
dict2.get(key,None)))
for key in set(dict1.keys()+dict2.keys())
)
(untested)
should provide you with a resulting dictonary with tuples
where [0] is var1 and [1] is var2, None for values not
in one of the dictionaries (you can put in 0 if you prefer).
You can use it like so to generate your output:
allitems=result.items()
allitems.sort() # sort based on keys as first tuple element
for (key,(var1,var2)) in allitems:
print key,var1,var2
HTH
Tino |
| |
| | | Raymond Hettinger | |
| | Posted: Tue Sep 02, 2008 3:18 pm Post subject: Re: dict.update | |
On Sep 2, 8:04 am, Mike P <michael.pearm...@tangozebra.com> wrote:
| Quote: | Hi All,
I have two dictionaries e.g
dict1 = {123:3,234:5,456:3}
dict2 = {123:4,157:2,234:5,456:3,567:2}
I want to merge these two dictionaries together so i have a resultant
dictionary of:
dict3 = {123:[4,3],157:[2,0],234:[5,5],456:[3,3],567:[2,0]}
As later on i want to write a csv file that would have the form
id var1 var2
123 4 3
157 2 0
i looks like the dict.update looks almost there but i can't get it to
work properly, can anyone offer any advise?
|
The update() method is not quite right for your purposes.
But a simple generator expression will do the trick:
| Quote: | dict((k, [v, dict1.get(k, 0)]) for k, v in dict2.items())
{456: [3, 3], 234: [5, 5], 123: [4, 3], 157: [2, 0], 567: [2, 0]} |
Raymond |
| |
| | | Mike P | |
| | Posted: Tue Sep 02, 2008 3:28 pm Post subject: Re: dict.update | |
Thanks Diez,
This is almost perfect!
Is there a way to ensure each list has two elements, even if one of
them is blank?
Mike |
| |
| | | Mike P | |
| | Posted: Tue Sep 02, 2008 3:31 pm Post subject: Re: dict.update | |
Thanks Raymond,
That's a neat trick, i'll look into learning more about this
Mike |
| |
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