CODEWITHSUNDEEP
python
winterli
winterli

Reputation: 84

how to write python to replace the next perl code?

I have just encountered Perl code similar to the following:

my @keys = qw/ 1 2 3 /;
my @vals = qw/ a b c /;
my %hash;
@hash{@keys} = @vals;

This code populates an associative array given a list of keys and a list of values. For example, the above code creates the following data structure (expressed as JSON):

{
    "1": "a",
    "2": "b",
    "3": "c"
}

How would one go about doing this in Python?

Upvotes: 1

Views: 74

Answers (3)

dawg
dawg

Reputation: 103884

You can do:

>>> keys='123'
>>> vals='abc'
>>> dict(zip(keys,vals))
{'1': 'a', '3': 'c', '2': 'b'}

(Python note: strings are iterable, so list('abc') is the rough equivalent of my @vals = qw/ a b c /; in Perl)

Then if you want JSON:

>>> import json
>>> json.dumps(dict(zip(keys,vals)))
'{"1": "a", "3": "c", "2": "b"}'

Upvotes: 1

Brian Cain
Brian Cain

Reputation: 14619

That json is pretty much a polyglot with Python. Once you assign it to a name, though, it stops being a polyglot.

hf = {
    "1": "a",
    "2": "b",
    "3": "c"
}

You can also iteratively align items into a dictionary.

letters = ('a', 'b', 'c', )
numbers = ('1', '2', '3', )
hf = { n : l for n, l in zip(numbers, letters) }

Upvotes: 1

Óscar López
Óscar López

Reputation: 236024

Like this:

import json

keys = [1, 2, 3]
vals = ['a', 'b', 'c']
hash = dict(zip(keys, vals))

json.dumps(hash)
=> '{"1": "a", "2": "b", "3": "c"}'

Upvotes: 1

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