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The pop( ) Function
The pop() function removes an element from the list based on the index number specified in the function and
returns the deleted value. In case no index number is given then by default it removes the last element from the
list. If we try to remove an index number which does not exist then it gives an IndexError.
For example,
Commands Output
vowels=['a', 'e', 'i', 'o', 'u'] 'i'
val=vowels.pop(2)
print(val)
val=vowels.pop() 'u'
print(val)
val=vowels.pop(6) IndexError: pop index out of range
print(val)
lst=[] IndexError: pop from empty list
lst.pop()
Some other Functions Used with List
There are some other functions also available to use with the list which are as follows:
• len(): This function returns the length of a list. For example,
marks = [10, 34, 42, 21, 45]
print(len(marks))
Output will be 5
• clear(): This function removes all the elements of the list in one go. It empties the list but the empty list still
exists in Python which can be used later to fill the values. For example,
city=["Delhi", "Mumbai", "Kolkata", "Chennai"]
city.clear()
print(city)
Output will be: [ ]
• reverse(): This function reverses the content of the list "in place". For example,
alpha = ['a', 'b', 'c', 'd', 'e']
alpha.reverse()
print(alpha)
Output will be: ['e', 'd', 'c', 'b', 'a']
• sort(): This function sorts the list in ascending or descending order. This is done "in the list itself" and works for
the list with values of the same data types. For example,
city=["Delhi", "Mumbai", "Kolkata", "Chennai"]
city.sort() #sorts the list by default in ascending order
print(city)
Introduction to Python 329

