# Python – All possible items combination dictionary

• Last Updated : 22 Apr, 2020

Sometimes, while working with data, we can have a problem in which we are provided with sample data of key and value list and we require to construct actual data as all possible combination of keys and value list of similar size. Lets discuss certain ways in which this task can be performed.

Method #1 : Using loop + `set()`
The combination of above functionalities can be employed to solve this problem. In this, we initially extract all items flattened in list of sets. Then we construct each dictionary using set subtraction.

 `# Python3 code to demonstrate working of ``# All possible items combination dictionary``# Using loop + set()`` ` `# initializing Dictionary``test_dict ``=` `{``'gfg'` `: [``1``, ``3``], ``'is'` `: [``5``, ``6``], ``'best'` `: [``4``, ``7``]}`` ` `# printing original dictionary``print``(``"The original dictionary is : "` `+` `str``(test_dict))`` ` `# All possible items combination dictionary``# Using loop + set()``temp ``=` `[``set``([key]) | ``set``(value) ``for` `key, value ``in` `test_dict.items() ]``res ``=` `{}``for` `sub ``in` `temp:``    ``for` `key ``in` `sub:``        ``res[key] ``=` `list``(sub ``-` `set``([key]))`` ` `# printing result ``print``(``"The all possible items dictionary : "` `+` `str``(res)) `

Output :

The original dictionary is : {‘is’: [5, 6], ‘gfg’: [1, 3], ‘best’: [4, 7]}
The all possible items dictionary : {1: [3, ‘gfg’], 3: [1, ‘gfg’], 4: [‘best’, 7], 5: [‘is’, 6], 6: [‘is’, 5], 7: [4, ‘best’], ‘best’: [4, 7], ‘is’: [5, 6], ‘gfg’: [1, 3]}

Method #2 : Using `remove() + loop + update()`
This is yet another way in which this task can be performed. In this, we perform the task of removal of values already present using remove() and construct new dictionary items.

 `# Python3 code to demonstrate working of ``# All possible items combination dictionary``# Using remove() + loop + update()`` ` `# initializing Dictionary``test_dict ``=` `{``'gfg'` `: [``1``, ``3``], ``'is'` `: [``5``, ``6``], ``'best'` `: [``4``, ``7``]}`` ` `# printing original dictionary``print``(``"The original dictionary is : "` `+` `str``(test_dict))`` ` `# All possible items combination dictionary``# Using remove() + loop + update()``res ``=` `{}``for` `key, val ``in` `test_dict.items():``    ``for` `ele ``in` `val:``        ``temp ``=` `val[:]``        ``temp.remove(ele)``        ``res.update({ele: [key] ``+` `temp})``test_dict.update(res)`` ` `# printing result ``print``(``"The all possible items dictionary : "` `+` `str``(test_dict)) `

Output :

The original dictionary is : {‘is’: [5, 6], ‘gfg’: [1, 3], ‘best’: [4, 7]}
The all possible items dictionary : {1: [3, ‘gfg’], 3: [1, ‘gfg’], 4: [‘best’, 7], 5: [‘is’, 6], 6: [‘is’, 5], 7: [4, ‘best’], ‘best’: [4, 7], ‘is’: [5, 6], ‘gfg’: [1, 3]}

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