a = [1, 2, 3] # list containing three integers
b = [a, "hello"] # list containing a list and a string
b.append(4) # modify existing list by appending an element
print(a)
print(b)
# Example: inserting, removing, and sorting elements
a = [1, 2, 3]
a.insert(1, 100) # insert 100 before index 1
print(a)
a.remove(2) # remove first occurrence of 2
print(a)
a.sort() # sort list
print(a)
a.extend([20, 21, 23]) # extend list with an additional list
print(a)
b = sorted(a)
print(b)
# Example: deleting an element
a = ['hello', ', ', 'world']
print(len(a))
del a[1]
print(len(a))
print(a)
# Example: the + operator
print([1, 2, 3] + [4, 5] + [6])
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