Re: Dictionary of Dicts question

[Chris Rebert]

On Thu, Oct 16, 2008 at 12:19 PM, John Townsend <jt******@adobe.comwrote:

I'm working with a Dictionary of Dicts. Something like this:

myDict = {
'TestName': {
'FileName':{

'ct_init':1234,

'psl_init':5678,

'total_test_time':7890,

'psl_shutdown':8765,

'ct_shutdown':9021,

'total_time':3421,
},
}
}

Accessing values is pretty straightforward (nice change from my Perl days).
For example:

myDict['TestName']['FileName']['ct_shutdown']

in Python interpreter yields

9021

However, when I try to add, let's say, a new FileName entry, I end up
replacing the previous FileName entry.

In Python interpreter, I try:

myDict['TestName'] = {'NewFileName': {}, }

I get

{'TestName': {'NewFileName': {}}}

Right, this clobbers the existing entry with this new blank one. This
is evidenced by the fact that you're performing an _assignment_ on a
dictionary key rather than calling a _mutator_ method on a dictionary
value. A dictionary has only one value for a given key (but
importantly, that value can be a list).

>
So, how do I add a new entry without replacing the old entry?

Switch to a Dict of Lists of Dicts and append to the appropriate list
when adding the new entry, or preferably, start using objects instead
of ad-hoc nested dictionaries.

Regards,
Chris
--
Follow the path of the Iguana...
http://rebertia.com

>
Thanks

John Townsend (5-7204),
AGM-FL and PSL QE Lead

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