# Python – Sublist Maximum in custom sliced List

• Last Updated : 01 Mar, 2020

Sometimes, while working with data, we can have a problem in which we need to extract maximum not of whole list but of certain customly broken sublists. This kind of problem is peculiar and occurs in many domains. Let’s discuss certain ways in which in which this task can be performed.

Method #1 : Using `itertools.islice() + max()` + list comprehension
The combination of above methods can be used to solve this problem. In this islice() is used to perform custom slicing and list comprehension is used to iterate and max() is used to compute maximum.

 `# Python3 code to demonstrate``# Sublist Maximum in custom sliced List``# using itertools.islice() + list comprehension``from` `itertools ``import` `islice`` ` `# initializing test list``test_list ``=` `[``1``, ``5``, ``3``, ``7``, ``8``, ``10``, ``11``, ``16``, ``9``, ``12``]`` ` `# initializing slice list ``slice_list ``=` `[``2``, ``1``, ``3``, ``4``]`` ` `# printing original list ``print``(``"The original list : "` `+` `str``(test_list))`` ` `# printing slice list ``print``(``"The slice list : "` `+` `str``(slice_list))`` ` `# using itertools.islice() + list comprehension``# Sublist Maximum in custom sliced List``temp ``=` `iter``(test_list)``res ``=` `[``max``(``list``(islice(temp, part))) ``for` `part ``in` `slice_list]`` ` `# print result``print``(``"The variable sliced list maximum is : "` `+` `str``(res))`
Output :
```The original list : [1, 5, 3, 7, 8, 10, 11, 16, 9, 12]
The slice list : [2, 1, 3, 4]
The variable sliced list maximum is : [5, 3, 10, 16]
```

Method #2 : Using `zip() + accumulate() + max()` + list slicing
Apart from using the list comprehension to perform the task of binding, this method uses zip function to hold sublist element together, accumulate function joins the elements, and slicing is used to construct the required slicing. The max() is used to perform maximum.

 `# Python3 code to demonstrate``# Sublist Maximum in custom sliced List``# using zip() + accumulate() + list slicing + max()``from` `itertools ``import` `accumulate`` ` `# initializing test list``test_list ``=` `[``1``, ``5``, ``3``, ``7``, ``8``, ``10``, ``11``, ``16``, ``9``, ``12``]`` ` `# initializing slice list ``slice_list ``=` `[``2``, ``1``, ``3``, ``4``]`` ` `# printing original list ``print``(``"The original list : "` `+` `str``(test_list))`` ` `# printing slice list ``print``(``"The slice list : "` `+` `str``(slice_list))`` ` `# using zip() + accumulate() + list slicing + max()``# Sublist Maximum in custom sliced List``res ``=` `[``max``(test_list[i ``-` `j: i]) ``for` `i, j ``in` `zip``(accumulate(slice_list), slice_list)]`` ` `# print result``print``(``"The variable sliced list maximum is : "` `+` `str``(res))`
Output :
```The original list : [1, 5, 3, 7, 8, 10, 11, 16, 9, 12]
The slice list : [2, 1, 3, 4]
The variable sliced list maximum is : [5, 3, 10, 16]
```

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