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Pythonic way to create a list from a nested dictionary

works in Python 2.7, I have a nested dictionary with some quotation data, from which I would like to create a list of successfully constructed quotes. Currently, here's how I do it:

result = []
for nameStr, nameData in dataTbl.iteritems():
    for valueDate, record in nameData.iteritems():
        quote = histRecordToQuote(securitiesDict = securitiesDict,
                                  nameStr        = nameStr,
                                  valueDate      = valueDate,
                                  record         = record)
        if quote:
            result.append(quote)

Is there a more pythonic way to do this? I have a hunch what we can do faster or more clearly with the list. The function histRecordToQuote()returns Nonewhen it cannot construct a quote due to a data error. You can suggest another signature, I will be glad to rewrite it for a clearer / faster code.

Many thanks.

EDIT

Dictionary structure example:

{'IBM':  {'20140215':2.53, '20140216':2.55},
 'MSFT': {'20140213':2.45, '20140216':0.},
 'AMZN': {'20140212':0., '20140214':2.59}}

The parameter securitiesDictis external, it is necessary to build the class Quoteinside histRecordToQuote().

histRecordToQuote() None 0 Quote .

Quote('IBM', '20140215', 2.53)
Quote('IBM', '20140216', 2.55)
Quote('MSFT', '20140213', 2.45)
None
Quote('AMZN', '20140214', 2.59)
None

:

[Quote('IBM', '20140215', 2.53),
Quote('IBM', '20140216', 2.55),
Quote('MSFT', '20140213', 2.45),
Quote('AMZN', '20140214', 2.59)]
+3
1

:

[ quote for quote in
    (histRecordToQuote(securitiesDict = securitiesDict,
                       nameStr        = nameStr,
                       valueDate      = valueDate,
                       record         = record)
      for nameStr, nameData in dataTbl.iteritems()
        for valueDate, record in nameData.iteritems())
    if quote ]
+2

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