Python List Exercises

There are hundreds of list exercises in Python.
Here are just a few of them.
I'm just working from web pages I found on the internet.
I intend to add to this over time.

# Print the last element on the list

# In Python, array indexes start with 0

# len[alist] prints the length

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mylist = ['a', 'b', 'c', 'd']

print ("last element: ", mylist [len(mylist)-1])

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last element:  d

# Find last but one in a list

# [Ummm, this is clearly harder in other languages]

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mylist = ['a', 'b', 'c', 'd']

print ("last element: ", mylist [len(mylist)-2])

last element:  c

# Find the ith element of a list where the first one starts at 1

i=7

mylist = ['a', 'b', 'c', 'd','e','f', 'g', 'h', 'i', 'j', 'k']

print(mylist[i-1])

g

# Find the number of elements of a list.

mylist = ['a', 'b', 'c', 'd','e','f', 'g', 'h', 'i', 'j', 'k']

print("Number of elements in list is: ", len(mylist))

Number of elements in list is:  11

# Reverse a list.

mylist = ['a', 'b', 'c', 'd','e','f', 'g', 'h', 'i', 'j', 'k']

# this works in place so you can't print it all on the same line

mylist.reverse()

print (mylist)

['k', 'j', 'i', 'h', 'g', 'f', 'e', 'd', 'c', 'b', 'a']

# Test if a list is a palindrome

# palindrome check - this is more convoluted than some but it helps to see the steps detailed

# Check if a given list is a palindrome

# Check indexes from 0 to the middle of the list

# Check if first index = last index, then move in by one

# Some diagnostics left in as comments

def palcheck(mylist):

 NotAPal = 0

 #print("Middle is: ",int(len(mylist)/2))

 #print ("Length of list: ", len(mylist))

 #print ("Last index: ", len(mylist)-1, "Contains: ", mylist[len(mylist)-1])

 lastindex = len(mylist)-1

 for i in range (0, int(len(mylist)/2)):

   if (mylist[i] != mylist[lastindex-i]):

     print(mylist, "is not a palindrome")

     NotAPal = 1

     break

 if (NotAPal == 0):

   print (mylist, "is a palindrome")

palcheck ([1,2,3,4,5,4,3,2,1])

palcheck ([1,2,3,4,2,3,2,1])

palcheck ([1,1,1,1])

palcheck ([1,2,3,2,1])

palcheck ([1,4,4,2,1])

[1, 2, 3, 4, 5, 4, 3, 2, 1] is a palindrome
[1, 2, 3, 4, 2, 3, 2, 1] is not a palindrome
[1, 1, 1, 1] is a palindrome
[1, 2, 3, 2, 1] is a palindrome
[1, 4, 4, 2, 1] is not a palindrome