Concatenate Some Lists X39029

Statement

Write a function $cat\_some(d, ks)$ that receives a dictionary $d$ and a list of possible keys $ks$ . The keys of $d$ are integers. The values are lists of integers. The returned result must be the concatenation of the lists corresponding in $d$ to the keys in $ks$ , in the same order the corresponding keys appear in $ks$ . Integers in $ks$ that do not appear in $d$ contribute an empty list to the result.

Observation

Please make sure to remove or comment out from the Jutge submission any doctesting code you might have in your source code.

Sample session

>>> cat_some({ 55: [0, 1, 4], 30: [-7, 7], 0: [0] }, [30, 55])
[-7, 7, 0, 1, 4]
>>> cat_some({ 55: [0, 1, 4], 30: [-7, 7], 0: [0], 2345: [ 23, 4, 56 ]  }, [ 0, 1, 2, 55, 0 ])
[0, 0, 1, 4, 0]
>>> cat_some({ 55: [0, 1, 4], 30: [0] }, [ 66, 55 ]) + cat_some({ 55: [0, 1, 4], 30: [0] }, [ 66, 55 ])
[0, 1, 4, 0, 1, 4]
>>> cat_some({ }, [ ])
[]

Information

Author
Language: English
Official solutions: Python
User solutions: Python