Using tuples to eliminate multiple dict values

[Benshep]

I need a dictionary that returns the same value for multiple keys.

i.e.

(1) >>> dict = { (1,2,3) : 'text' , (5,6,7) : 'other text' }
(2) >>>dict[1]
(3) 'text'

I cant figure out what i need on line 2 to make this scenario work. Is
there a simple way to check if the a number is present in the key and
then return the value?

Thanks

 

[Prasad, Ramit]

-----Original Message-----
From: [email protected] [mailto[email protected]] On Behalf Of Benshep
Sent: Friday, September 16, 2011 1:48 PM
To: (e-mail address removed)
Subject: Using tuples to eliminate multiple dict values

I need a dictionary that returns the same value for multiple keys.

i.e.

(1) >>> dict = { (1,2,3) : 'text' , (5,6,7) : 'other text' }
(2) >>>dict[1]
(3) 'text'

I cant figure out what i need on line 2 to make this scenario work. Is
there a simple way to check if the a number is present in the key and
then return the value?

Thanks
----------------------------------------------------------------

I think I must be missing something. Can you not do the following?

d = { 1:'text', 2:'text', 3:'text', 5:'other text', 6:'other text', 7:'other text' }
d[1]

'text'



If you are they need to share the same value you can also do something like this.

t1 = [ 'text' ]
t2 = [ 'other text' ]
d = { 1:t1, 2:t1, 3:t1, 5:t2, 6:t2, 7:t2 }
d[1]
['text']
d[1][0]='new text'
d[2][0]
'newtext'
d

{1: ['new text'], 2: ['new text'], 3: ['new text'], 5: ['other text'], 6: ['other text'], 7: ['other text']}


Ramit


Ramit Prasad | JPMorgan Chase Investment Bank | Currencies Technology
712 Main Street | Houston, TX 77002
work phone: 713 - 216 - 5423



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[MRAB]

I need a dictionary that returns the same value for multiple keys.

i.e.

(1)>>> dict = { (1,2,3) : 'text' , (5,6,7) : 'other text' }

That will create a dict with 2 keys, both of which are tuples.

(2)>>>dict[1]
(3) 'text'

I cant figure out what i need on line 2 to make this scenario work. Is
there a simple way to check if the a number is present in the key and
then return the value?

If you want multiple keys, then you must provide them separately:

my_dict = {1: 'text', 2: 'text', 3: 'text', 5: 'other text', 6 : 'other
text', 7: 'other text'}

or use 'for' to iterate through the keys for each value:

my_dict = dict([(k, 'text') for k in (1, 2, 3)] + [(k, 'other text') for
k in (5, 6, 7)])

or something similar.

 

[Benshep]

thanks,

I had a feeling that may be the way to go and my data just changed so
it will work better that way.

Thanks for the quick reply

 

[Chris Angelico]

(1)   >>> dict = { (1,2,3) : 'text' , (5,6,7) : 'other text' }

As I understand it, you're looking for a simple syntax for what MRAB posted:

my_dict = {1: 'text', 2: 'text', 3: 'text', 5: 'other text', 6 : 'othertext', 7: 'other text'}

Since your first line of code is syntactically legal, you could do a
simple check afterwards to translate it:

my_dict = { (1,2,3) : 'text' , (5,6,7) : 'other text' }
for k in list(my_dict.keys()):
if isinstance(k,tuple):
val=my_dict.pop(k)
for i in k: my_dict=val

Tested in Python 3.2; in Python 2, the list() call is superfluous,
everything else should work fine.

Chris Angelico

 

[Tim Chase]

I need a dictionary that returns the same value for multiple keys.

i.e.

(1)>>> dict = { (1,2,3) : 'text' , (5,6,7) : 'other text' }
(2)>>>dict[1]
(3) 'text'

I cant figure out what i need on line 2 to make this scenario work. Is
there a simple way to check if the a number is present in the key and
then return the value?

You could use something like

d = dict(
(k,v)
for keys in (
((1,2,3), 'text'),
((5,6,7), 'other text'),
)
for k in keys
)

which seems to do what you want with minimal redundancy of
declarations.

-