Python | Get the Index of first element greater than K

Python list operations are always desired to have shorthands as they are used in many places in development. Hence having knowledge of them always remains quite useful.
Let’s deals with finding one such utility of having index of first element greater than K by one-liner. There are various ways in which this can be achieved.

Method #1 : Using next() + enumerate()
Using next() returns the iterator to the element that has been using the enumerate(). We simply put the condition for enumerate and next() picks appropriate element index.

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# Python3 code to demonstrate 
# to find index of first element just 
# greater than K 
# using enumerate() + next()
  
# initializing list
test_list = [0.4, 0.5, 11.2, 8.4, 10.4]
  
# printing original list
print ("The original list is : " + str(test_list))
  
# using enumerate() + next() to find index of
# first element just greater than 0.6 
res = next(x for x, val in enumerate(test_list)
                                  if val > 0.6)
  
# printing result
print ("The index of element just greater than 0.6 : "
                                           + str(res))

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Output:



The original list is : [0.4, 0.5, 11.2, 8.4, 10.4]
The index of element just greater than 0.6 : 2

 
Method #2 : Using filter() + lambda
Using filter along with lambda can also help us to achieve this particular task, subscript index value 0 is used to specify that first element greater than value has to be taken.

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# Python3 code to demonstrate 
# to find index of first element just 
# greater than K 
# using filter() + lambda
  
# initializing list
test_list = [0.4, 0.5, 11.2, 8.4, 10.4]
  
# printing original list
print ("The original list is : " + str(test_list))
  
# using filter() + lambda
# to find index of first element just 
# greater than 0.6 
res = list(filter(lambda i: i > 0.6, test_list))[0]
  
# printing result
print ("The index of element just greater than 0.6 : "
                          + str(test_list.index(res)))

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Output:

The original list is : [0.4, 0.5, 11.2, 8.4, 10.4]
The index of element just greater than 0.6 : 2

 
Method #3 : Using map() + index()
map() along with the index() can also return the desired element index and has the similar internal working as method 1 as discussed above.

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# Python3 code to demonstrate 
# to find index of first element just 
# greater than K 
# using map() + index()
  
# initializing list
test_list = [0.4, 0.5, 11.2, 8.4, 10.4]
  
# printing original list
print ("The original list is : " + str(test_list))
  
# using map() + index()
# to find index of first element just 
# greater than 0.6 
res = list(map(lambda i: i> 0.6, test_list)).index(True)
  
# printing result
print ("The index of element just greater than 0.6 : "
                                           + str(res))

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Output:

The original list is : [0.4, 0.5, 11.2, 8.4, 10.4]
The index of element just greater than 0.6 : 2


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