Sometimes, while working with data in form of records, we can have a problem in which we need to find the maximum element of all the records received. This is a very common application that can occur in Data Science domain. Let’s discuss certain ways in which this task can be performed.
Method #1: Using max() + generator expression This is the most basic method to achieve the solution to this task. In this, we iterate over whole nested lists using generator expression and get the maximum element using max().
Python3
# Python3 code to demonstrate working of# Maximum element in tuple list# using max() + generator expression# initialize listtest_list = [(2, 4), (6, 7), (5, 1), (6, 10), (8, 7)]# printing original listprint("The original list : " + str(test_list))# Maximum element in tuple list# using max() + generator expressionres = max(int(j) for i in test_list for j in i)# printing resultprint("The Maximum element of list is : " + str(res)) |
The original list : [(2, 4), (6, 7), (5, 1), (6, 10), (8, 7)] The Maximum element of list is : 10
Method #2 : Using max() + map() + chain.from_iterable() The combination of above methods can also be used to perform this task. In this, the extension of finding maximum is done by combination of map() and from_iterable().
Python3
# Python3 code to demonstrate working of# Maximum element in tuple list# using max() + map() + chain.from_iterable()from itertools import chain# initialize listtest_list = [(2, 4), (6, 7), (5, 1), (6, 10), (8, 7)]# printing original listprint("The original list : " + str(test_list))# Maximum element in tuple list# using max() + map() + chain.from_iterable()res = max(map(int, chain.from_iterable(test_list)))# printing resultprint("The Maximum element of list is : " + str(res)) |
The original list : [(2, 4), (6, 7), (5, 1), (6, 10), (8, 7)] The Maximum element of list is : 10
Method #3: Using list comprehension method
Python3
test_list = [(2, 4), (6, 7), (5, 1), (6, 10), (8, 7)] x=[j for i in test_list for j in i ]print(max(x)) |
10
Method #4: Using enumerate function
Python3
test_list = [(2, 4), (6, 7), (5, 1), (6, 10), (8, 7)] x=[j for a,i in enumerate(test_list) for j in i ]print(max(x)) |
10
Method #5: Using itemgetter
Python3
from operator import itemgettermy_list = [('Will', 23), ('Jane', 21), ('El', 24), ('Min', 101)]my_result = max(my_list, key = itemgetter(1))[1]print ("The maximum value is : ")print(my_result) |
The maximum value is : 101
Method #6: Using the lambda function
Python3
test_list = [(2, 4), (6, 7), (5, 1), (6, 10), (8, 7)]x=[j for i in test_list for j in i ]x=list(filter(lambda i: (i),x))print(max(x)) |
10
Method #7: Using extend() and max() methods
Python3
# Python3 code to demonstrate working of# Maximum element in tuple list# initialize listtest_list = [(2, 4), (6, 7), (5, 1), (6, 10), (8, 7)]# printing original listprint("The original list : " + str(test_list))# Maximum element in tuple listx=[]for i in test_list: x.extend(list(i))res=max(x)# printing resultprint("The Maximum element of list is : " + str(res)) |
The original list : [(2, 4), (6, 7), (5, 1), (6, 10), (8, 7)] The Maximum element of list is : 10
Method #8: Using numpy.max()
Note: Install numpy module using command “pip install numpy”
You can use numpy.max() to find the maximum element in the tuple list.
Python3
import numpy as np# initialize listtest_list = [(2, 4), (6, 7), (5, 1), (6, 10), (8, 7)]# printing original listprint("The original list : " + str(test_list))# Maximum element in tuple list# using numpy.max()res = np.max(test_list)# printing resultprint("The Maximum element of list is : " + str(res))#This code is contributed by Edula Vinay Kumar Reddy |
Output:
The original list : [(2, 4), (6, 7), (5, 1), (6, 10), (8, 7)]
The Maximum element of list is : 10
method has the time complexity of O(n) where n is the number of elements in the list. Auxiliary Space is O(1)
Method #9:Using reduce
Algorithm:
- Initialize a list of tuples.
- Flatten the list of tuples into a single list of integers using reduce.
- Remove any 0 or False values from the flattened list using filter.
- Find the maximum value in the filtered list using max.
- Print the maximum value.
Python3
from functools import reducetest_list = [(2, 4), (6, 7), (5, 1), (6, 10), (8, 7)]# printing original listprint("The original list : " + str(test_list))# Use reduce to flatten the list of tuples into a single list of integersflat_list = reduce(lambda acc, x: acc + list(x), test_list, [])# Use filter to remove any 0 or False values from the listfiltered_list = list(filter(lambda x: x, flat_list))# Find the maximum value in the filtered listres = max(filtered_list)# printing resultprint("The Maximum element of list is : " + str(res))#This code is contributed by Vinay Pinjala. |
The original list : [(2, 4), (6, 7), (5, 1), (6, 10), (8, 7)] The Maximum element of list is : 10
Time complexity is O(n)
In the case of the provided code, the time complexity is O(n), where n is the total number of elements in the list of tuples. This is due to the fact that the most time-consuming operations in the code involve iterating through the list of tuples, flattening it using reduce, and filtering out any 0 or False values using filter. These operations take linear time as a function of the input size, and therefore contribute to the overall O(n) time complexity.
space complexity is also O(n)
where n is the total number of elements in the list of tuples. This is due to the fact that the code requires a certain amount of memory to store the list of tuples, flatten it using reduce, and filter out any 0 or False values using filter. These operations require memory proportional to the size of the input, and therefore contribute to the overall O(n) space complexity.
