Getting a list of values from a list of dicts

Question

I have a list of dicts like this:

[{\'value\': \'apple\', \'blah\': 2}, 
 {\'value\': \'banana\', \'blah\': 3} , 
 {\'value\': \'cars\', \'blah\': 4}]
         


        

Answer 1

Here's another way to do it using map() and lambda functions:

>>> map(lambda d: d['value'], l)

where l is the list. I see this way "sexiest", but I would do it using the list comprehension.

Update: In case that 'value' might be missing as a key use:

>>> map(lambda d: d.get('value', 'default value'), l)

Update: I'm also not a big fan of lambdas, I prefer to name things... this is how I would do it with that in mind:

>>> import operator
>>> map(operator.itemgetter('value'), l)

I would even go further and create a sole function that explicitly says what I want to achieve:

>>> import operator, functools
>>> get_values = functools.partial(map, operator.itemgetter('value'))
>>> get_values(l)
... []

With Python 3, since map returns an iterator, use list to return a list, e.g. list(map(operator.itemgetter('value'), l)).