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Python: Find the second largest number in a list

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 :

Python: Find the second largest number in a list

Example - 3 :

Python: Find the second largest number in a list

Example - 4 :

Python: Find the second largest number in a list

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:

Flowchart: Find the second largest number in a list

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Python: Tips of the Day

Python: The Zip() Function

>>> students = ('John', 'Mary', 'Mike')
>>> ages = (15, 17, 16)
>>> scores = (90, 88, 82, 17, 14)
>>> for student, age, score in zip(students, ages, scores):
...     print(f'{student}, age: {age}, score: {score}')
... 
John, age: 15, score: 90
Mary, age: 17, score: 88
Mike, age: 16, score: 82
>>> zipped = zip(students, ages, scores)
>>> a, b, c = zip(*zipped)
>>> print(b)
(15, 17, 16)