CODEWITHSUNDEEP
pythondictionary
devdropper87
devdropper87

Reputation: 4187

Filter a dictionary if value of a key is true

I am totally new to Python (day 1). I have a dataset that indicates whether someone is a person of interest via a boolean 'poi' key. I was able to filter the data with the following:

filtered = []
for n in enron_data:
    if enron_data[n]['poi']: filtered.append(enron_data[n]);
print(len(filtered))

I tried for a while to use pythons built in filter but was unable to. what is a clean way to do this with the builtin filter?

example data: {'METTS MARK': {... 'poi': False,}, ...}

Upvotes: 8

Views: 12265

Answers (4)

Ehiz Ize
Ehiz Ize

Reputation: 29

d = {1:11, 2:22, 3:33}

# filter by value
d3 = {}

for key,value in d.items():
    if value in [22,33]:
        d3.update({key:value})
print(d3)

Upvotes: 0

nivhanin
nivhanin

Reputation: 1908

Another filter function

new_list = filter(your_dict.get, your_dict)

Less expensive than using lambda inside the filter function.

Upvotes: 4

Robert Seaman
Robert Seaman

Reputation: 2582

You can use list comprehension to iterate over the dictionary to then create a new list of the values that evaluate True for value['poi'].

filtered = [v for k, v in enron_data.items() if v['poi']]

In fact, you're not using the keys at all, so you could just do:

filtered = [v for v in enron_data.values() if v['poi']]

Or to use filter (similar to @AbidHasan):

filtered = filter(lambda x: x['poi'], enron_data.values())

Upvotes: 12

Abid Hasan
Abid Hasan

Reputation: 658

You could also use the filter function.

new_list = filter(lambda x: a[x]['POI'], a)

Upvotes: 1

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