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Python: Find the index of the first element in the given list that satisfies the provided testing function

Python List: Exercise - 229 with Solution

Write a Python program to find the index of the first element in the given list that satisfies the provided testing function.

Use a list comprehension, enumerate() and next() to return the index of the first element in nums for which fn returns True.

Sample Solution:

Python Code:

def find_index(nums, fn):
  return next(i for i, x in enumerate(nums) if fn(x))
print(find_index([1, 2, 3, 4], lambda n: n % 2 == 1))

Sample Output: 

0

Flowchart:

Flowchart: Find the index of the first element in the given list that satisfies the provided testing function.

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Previous: Write a Python program to get every element that exists in any of the two given lists once, after applying the provided function to each element of both.
Next: Write a Python program to find the indexes of all elements in the given list that satisfy the provided testing function.

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Python: Tips of the Day

Given a predicate function, fn, and a prop string, this curried function will then take an object to inspect by calling the property and passing it to the predicate:

Example:

def tips_check_prop(fn, prop):
  return lambda obj: fn(obj[prop])
check_age = tips_check_prop(lambda x: x >= 25, 'age')
user = {'name': 'Owen', 'age': 25}

print(check_age(user))

Output:

True

 

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