Question

Python 3

Implement the function invert_and_merge, which takes any number of input dictionaries via a star parameter, and inverts and merges them into a single result dictionary. When inverting a dictionary, the keys and values are flipped, so that each value maps to a set containing the corresponding key(s) in the original dictionary. When merging the inverted dictionaries, sets corresponding to the same key are combined.

Examples:

• invert_and_merge({'a': 1, 'b': 2, 'c': 1, 'd': 1, 'e': 2})
  should return {1: {'a', 'c', 'd'}, 2: {'b', 'e'}}
• invert_and_merge({'a': 'apple', 'b': 'bee', 'c': 'cat'},
  {'insect': 'bee', 'mammal': 'cat', 'feline': 'cat'},
  {'citrus': 'orange', 'pome': 'apple', 'pollinator': 'bee'})
  should return {'apple': {'a', 'pome'},
  'bee': {'b', 'insect', 'pollinator'},
  'cat': {'c', 'feline', 'mammal'},
  'orange': {'citrus'}}

def invert_and_merge(*dicts):
rdict = {}
# YOUR CODE HERE
return rdict

Answer 1

Code

def invert_and_merge(*dicts):

rdict = {}

#iterate the dicts

for i in dicts:

for item,value in i.items():

#cehck if value is in rdict

#if yes then add the value to the place

if value in rdict:

rdict[value].add(item)

#else create new entry in rdict

else:

rdict[value]={item}

return rdict

print(invert_and_merge({'a': 1, 'b': 2, 'c': 1, 'd': 1, 'e': 2}))

print(invert_and_merge({'a': 'apple', 'b': 'bee', 'c': 'cat'},

{'insect': 'bee', 'mammal': 'cat', 'feline': 'cat'},

{'citrus': 'orange', 'pome': 'apple', 'pollinator': 'bee'}))

Screenshot

Output