w3resource

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

Python List: Exercise - 239 with Solution

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

Use a list comprehension and next() to return the first element in lst for which fn returns True.

Sample Solution:

Python Code:

# Define a function 'find' that takes a list 'lst' and a function 'fn' as input.
def find(lst, fn):
    # Use a generator expression to find the first element 'x' in the list 'lst' for which 'fn(x)' is true.
    # The 'next' function is used to retrieve the first matching element.
    return next(x for x in lst if fn(x))

# Call the 'find' function with a list and a lambda function to find the first odd number in the list.
# Print the result.
print(find([1, 2, 3, 4], lambda n: n % 2 == 1))
# Call the 'find' function again with a lambda function to find the first even number in the list.
# Print the result.
print(find([1, 2, 3, 4], lambda n: n % 2 == 0))

Sample Output:

1
2

Flowchart:

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

Python Code Editor:

Previous: Write a Python program to calculate the average of a given list, after mapping each element to a value using the provided function.
Next: Write a Python program to find the value of the last element in the given list that satisfies the provided testing function.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Follow us on Facebook and Twitter for latest update.