12 - Loops II - lists.ipynb

Kernel: Python 3 (system-wide)

Exercise 12.1

Loop through the following list and print out each word.

words = ['golf', 'level', 'spoon', 'reverser', 'noon', 'racecar', 'cell', 'rotator', 'tape', 'stats', 'bridge', 'lagoon', 'tenet']

for i in words:
    print(i)

golf
level
spoon
reverser
noon
racecar
cell
rotator
tape
stats
bridge
lagoon
tenet

Exercise 12.2

Loop through the following list and print out the reverse of each word.

words = ['golf', 'level', 'spoon', 'reverser', 'noon', 'racecar', 'cell', 'rotator', 'tape', 'stats', 'bridge', 'lagoon', 'tenet']

for i in words:
    print(i[::-1])

flog
level
noops
resrever
noon
racecar
llec
rotator
epat
stats
egdirb
noogal
tenet

Exercise 12.3

Loop through the following list of DNA sequences. Test and print if the start codon "ATG" is in each sequence.

DNA_sequences = ['TATCATGGTAGAT', 'TATATCGCTAGGG', 'CTATAGCCTAGGA', 'TATGAGGATTAGA', 'TATAGACTAGGAT']

for i in DNA_sequences:
    if 'ATG' in i:
        print('yes')
        
    else:
        print('no')

yes
no
no
yes
no

Exercise 12.4

Loop through the following list of measurements of female haemoglobin levels. Test and print if each measurement is between the normal values of 11.6 and 15.0 g/dl.

haemoglobin_levels = [12.5, 15.1, 12.6, 10.4, 15.7, 9.2, 17.6, 12.9, 10.6, 12.3, 17.9, 14.0, 15.5, 12.5, 10.6]

for i in haemoglobin_levels:
    
    if i > 11.6 and i < 15.0:
        print('between the normal values of 11.6 and 15.0 g/dl.')
        
    else:
        print('not between the normal values of 11.6 and 15.0 g/dl.')

between the normal values of 11.6 and 15.0 g/dl.
not between the normal values of 11.6 and 15.0 g/dl.
between the normal values of 11.6 and 15.0 g/dl.
not between the normal values of 11.6 and 15.0 g/dl.
not between the normal values of 11.6 and 15.0 g/dl.
not between the normal values of 11.6 and 15.0 g/dl.
not between the normal values of 11.6 and 15.0 g/dl.
between the normal values of 11.6 and 15.0 g/dl.
not between the normal values of 11.6 and 15.0 g/dl.
between the normal values of 11.6 and 15.0 g/dl.
not between the normal values of 11.6 and 15.0 g/dl.
between the normal values of 11.6 and 15.0 g/dl.
not between the normal values of 11.6 and 15.0 g/dl.
between the normal values of 11.6 and 15.0 g/dl.
not between the normal values of 11.6 and 15.0 g/dl.

Exercise 12.5

The number of items in a list is given by the len() function.

1. Write your own code that counts the number items in a list and prints it out.

2. Test your code on any of the lists in these exercises.

count = 0

for i in haemoglobin_levels:
    if i != '':
        count += 1
        
print (count)
print(len(haemoglobin_levels))

15
15

Exercise 12.6

Create an new list called squares of the squares of each number in the list numbers below. That is, the new list should be [1, 4, 9, etc.].

• Hint: Create an empty list, loop through the list numbers and append the square of each number to the new list.

numbers = [1, 2, 3, 4, 5, 6, 7]
squares = []

for i in numbers:
    squares.append(i**2)
    
print(squares)

[1, 4, 9, 16, 25, 36, 49]