Combining 2d Arrays

Question

Suppose I have two arrays:

arrayOne = [["james", 35], ["michael", 28], ["steven", 23], 
            ["jack", 18], ["robert", 12]]
arrayTwo = [["charles", 45], ["james",  36], ["trevor", 24], 
            ["michael", 17], ["steven", 4]]

I want to combine them so that I have one 2D array, where the first element of each internal array is the name (james, charles, etc.). The second element of the internal array is its corresponding value in arrayOne, and if it does not have the corresponding value, it will be 0. And vice versa, for the third element. The order does not matter if the numbers match the name. In other words, I would get something like this

arrayResult = [["james", 35, 36], ["michael", 28, 17], ["steven", 23, 4],
               ["jack", 18, 0], ["robert", 12, 0], ["charles", 0, 45],
               ["trevor", 0, 4]]

Also, I'm trying to use it to add more columns to this array result if I have to provide another array.

Answer 1

, , . , . dicts :

dictOne = dict(arrayOne)
dictTwo = dict(arrayTwo)

:

combined = dict()
for name in set(dictOne.keys() + dictTwo.keys()):
  combined[name] = [ dictOne.get(name, 0), dictTwo.get(name, 0) ]

, combined, . . , . , combined, .get 0, . , :

arrayResult = []
for name in combined:
  arrayResult.append([ name ] + combined[name])

, , , , , :

combined = dict()
for name in set(dictOne.keys() + dictTwo.keys() + dictThree.keys()):
  combined[name] = [ dictOne.get(name, 0), dictTwo.get(name, 0), dictThree.get(name, 0) ]

( ), :

def combine(*args):
  # Create a list of dictionaries from the arrays we passed in, since we are
  # going to use dictionaries to solve the problem.
  dicts = [ dict(a) for a in args ]

  # Create a list of names by looping through all dictionaries, and through all
  # the names in each dictionary, adding to a master list of names
  names = []
  for d in dicts:
    for name in d.keys():
      names.append(name)

  # Remove duplicates in our list of names by making it a set
  names = set(names)

  # Create a result dict to store results in
  result = dict()

  # Loop through all the names, and add a row for each name, pulling data from
  # each dict we created in the beginning
  for name in names:
    result[name] = [ d.get(name, 0) for d in dicts ]

  # Return, secure in the knowledge of a job well done. :-)
  return result

# Use the function:
resultDict = combine(arrayOne, arrayTwo, arrayThree)

Answer 2

>>> dict1 = dict(arrayOne)
>>> dict2 = dict(arrayTwo)
>>> keyset = set(dict1.keys() + dict2.keys())
>>> [[key, dict1.get(key, 0), dict2.get(key, 0)] for key in keyset]
[['james', 35, 36], ['robert', 12, 0], ['charles', 0, 45], 
 ['michael', 28, 17], ['trevor', 0, 24], ['jack', 18, 0], 
 ['steven', 23, 4]]

, ; . 0 , " ", , 0 . , :

def add_column(masterdict, arr):
    mdlen = len(masterdict[masterdict.keys()[0]])
    newdict = dict(arr)
    keyset = set(masterdict.keys() + newdict.keys())
    for key in keyset:
        if key not in masterdict:
            masterdict[key] = [0] * mdlen
        masterdict[key].append(newdict.get(key, 0))

arrayOne =   [["james", 35],
              ["michael", 28],
              ["steven", 23],
              ["jack", 18],
              ["robert", 12]]
arrayTwo =   [["charles", 45],
              ["james",  36],
              ["trevor", 24],
              ["michael", 17],
              ["steven", 4]]
arrayThree = [["olliver", 11],
              ["james",  39],
              ["john", 22],
              ["michael", 13],
              ["steven", 6]]

masterdict = dict([(i[0], [i[1]]) for i in arrayOne])

add_column(masterdict, arrayTwo)
print masterdict
add_column(masterdict, arrayThree)
print masterdict

:

{'james': [35, 36], 'robert': [12, 0], 'charles': [0, 45], 
 'michael': [28, 17], 'trevor': [0, 24], 'jack': [18, 0], 
 'steven': [23, 4]}
{'james': [35, 36, 39], 'robert': [12, 0, 0], 'charles': [0, 45, 0], 
  'michael': [28, 17, 13], 'trevor': [0, 24, 0], 'olliver': [0, 0, 11], 
  'jack': [18, 0, 0], 'steven': [23, 4, 6], 'john': [0, 0, 22]}