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Python | K Value Indices Product
• Last Updated : 27 Feb, 2020

Usually, we require to find the index, in which the particular value is located. There are many method to achieve that, using index() etc. But sometimes require to find all the indices of a particular value in case it has multiple occurrences in list and compute their product. Lets discuss certain ways to do so.

Method #1 : Naive Method
We can achieve this task by iterating through the list and check for that value and just append the value index in new list and print that. This is the basic brute force method to achieve this task. The task of performing product is done by loop.

 # Python code to demonstrate # K Value Indices Product# using naive method   # initializing list test_list = [1, 3, 4, 3, 6, 7, 3]  # printing initial list print ("Original list : " + str(test_list))  # initializing K K = 3  # using naive method# K Value Indices Productres = 1for i in range(0, len(test_list)) :    if test_list[i] == K :        res *= i  # printing resultant list print ("K Value indices product is : " + str(res))
Output :
Original list : [1, 3, 4, 3, 6, 7, 3]
K Value indices product is : 18

Method #2 : Using enumerate() + loop
Using enumerate() we can achieve the similar task, this is slightly faster technique than above and hence is recommended to be used over the list comprehension technique. The task of performing product is done by loop.

 # Python code to demonstrate # K Value Indices Product# using enumerate()  # getting Product def prod(val) :     res = 1     for ele in val:         res *= ele     return res    # initializing list test_list = [1, 3, 4, 3, 6, 7, 3]  # printing initial list print ("Original list : " + str(test_list))  # initializing K K = 3  # using enumerate()# K Value Indices Productres = prod([i for i, value in enumerate(test_list) if value == K])  # printing resultant list print ("K Value indices product is : " + str(res))
Output :
Original list : [1, 3, 4, 3, 6, 7, 3]
K Value indices product is : 18

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