Sort dictionary by multiple values, where amount of values can vary-CodePudding

To come straight to the point:

def sortBy(dict, byWhat):

  # byWhat is a list of 1 - 10 strings, which can include any of allAttributes
  # allAttributes = ['name', 'kingdom', 'diff', 'tier', 'type', 'founder', 'prover', 'server', 'extra', 'link']
  # the lower the index, the higher the sorting priority -> byWhat = ['name', 'diff'] then sort by name first and then if names are the same by diff
  
  # dict has the name as key and then allAttributes above in order as a list for the key's value, so for example:
  # dict[Jump] = [Jump, Mushroom Kingdom, 10/10, Triple Jump, Dude, Dude2, Main Server, Cool jump description, https://twitter.com]
  # All dictionary entries have those 10 attributes, no exceptions
  
  return dict # but sorted

I tried for a while but where my knowledge ends is sorting by a varying size of specifiers with lambda. I can also not just call the function multiple times, because then it won't sort by two attributes, but by the last attribute the function got called with.

CodePudding user response：

You can convert dict to list of (key, value) tuples and use list.sort(key) method and utilizing functools.cmp_to_key define key as compare function and then "inject" byWhat parameter into compare function using functools.partial

from functools import cmp_to_key, partial

allAttributes = ["name", "age"]

def sortBy(d, byWhat):
    def cmp(a, b, byWhat):
        for k in byWhat:
            index = allAttributes.index(k)
            if a[1][index] != b[1][index]:
                return -1 if a[1][index] < b[1][index] else 1
        return 0
    items = list(d.items())
    items.sort(key=cmp_to_key(partial(cmp, byWhat=byWhat)))
    return dict(items)

if __name__ == "__main__":
    d = {
        "foo": ["John", 12],
        "bar": ["Adam", 12],
        "baz": ["John", 10],
    }
    print(sortBy(d, ["name", "age"]))

CodePudding user response：

You can convert dict to list of (key, value) tuples, map byWhat into indexes and use list.sort(key) where key is lambda returning list of attributes to sort by.

allAttributes = ["name", "age"]

def sortBy(d, byWhat):
    indexes = [allAttributes.index(k) for k in byWhat]
    items = list(d.items())
    items.sort(key=lambda item: [item[1][index] for index in indexes])
    return dict(items)

if __name__ == "__main__":
    d = {
        "foo": ["John", 12],
        "bar": ["Adam", 12],
        "baz": ["John", 10],
    }
    print(sortBy(d, ["name", "age"]))