# SCMA241 Lab : Lists

In [1]:
# create an empty list and initialize its values by random numbers
import random

number = int(input('Enter the length of the list : '))

# (1) create a list
my_list = [0]*number

# (2) assign values to elements of the list
for i in range(number):
my_list[i] = random.randint(1,100)

# (3) print the list
print(my_list)

Enter the length of the list : 5
[88, 32, 16, 43, 17]

In [2]:
# count the number of odd and even numbers in the list
#
import random

def count_odd(my_list):
# count the number of odd numbers
num_odd = 0

for num in my_list:
if num%2 == 1:
num_odd += 1

return num_odd

def count_even(my_list):
# count the number of even numbers
num_even = 0

for num in my_list:
if num%2 == 0:
num_even += 1

return num_even

# define the main function
def main():

number = int(input('Enter the length of the list : '))

my_list = [0]*number

for i in range(number):
my_list[i] = random.randint(1,100)

print(my_list)

# call the function
num_odd = count_odd(my_list)
num_even = count_even(my_list)

print(num_odd,num_even)

# call the main function
main()

Enter the length of the list : 10
[20, 9, 5, 54, 78, 56, 41, 14, 23, 38]
4 6

In [3]:
# indexing and slicing : write a function that receives a list as an argument and
# computes the square of each element in the list.

len(my_list)

Out[3]:
5
In [4]:
# write a function that returns the length of a list (without using len() function).
#
def my_len(my_list):
# find the length of the list
length = 0

for num in my_list:
length += 1

return length

# define the main function
def main():
mylist = [1,2,3,4,5,6,7]
length = my_len(mylist)

print('The length of this list is ', length)

# call the main function
main()

The length of this list is  7

In [7]:
# write a program that converts a string into a list and print it in reverse order.
#
def print_reverse(mystr):
# print a string in reverse

my_list = list(mystr)
for i in range(len(my_list)):
print(my_list[len(my_list)-i-1],end='')

# define the main function
def main():
name = "Krikamol"
print_reverse(name)

# call the main function
main()

lomakirK
In [8]:
# write a function that counts the number of unique elements in a list (enumerate function).
#
def count_unique(my_list):
# count the number of unique elements
num_unique = 0

for i in range(len(my_list)):
is_unique = True

for j in range(i):
if my_list[i] == my_list[j]:
is_unique = False
break

if is_unique:
num_unique += 1

return num_unique

# define the main function
def main():
mylist = [2,3,2,7,4,3]
num_unique = count_unique(mylist)

print('The number of unique elements is ', num_unique)

# call the main function
main()

The number of unique elements is  4

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