Python: Find the second largest number in a list

Last update on August 19 2022 21:51:46 (UTC/GMT +8 hours)

Python List: Exercise - 28 with Solution

Write a Python program to find the second largest number in a list.

Example - 1 :

Python: Find the second largest number in a list

Example - 2 :

Example - 3 :

Example - 4 :

Sample Solution:-

Python Code:

def second_largest(numbers):
  if (len(numbers)<2):
    return
  if ((len(numbers)==2)  and (numbers[0] == numbers[1]) ):
    return
  dup_items = set()
  uniq_items = []
  for x in numbers:
    if x not in dup_items:
      uniq_items.append(x)
      dup_items.add(x)
  uniq_items.sort()    
  return  uniq_items[-2]   
print(second_largest([1,2,3,4,4]))
print(second_largest([1, 1, 1, 0, 0, 0, 2, -2, -2]))
print(second_largest([2,2]))
print(second_largest([1]))

Sample Output:

3
1
None
None

Flowchart:

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Previous: Write a Python program to find the second smallest number in a list.
Next: Write a Python program to get unique values from a list.

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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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