Ways to compute the squares of the integers between 1 and 5

On this page click on the code samples to execute them.

1. The for loop combined with the range function is the most direct approach:

   for i in range(1, 6):
       print(i**2)
   

2. It is also possible to combine a while loop with the incrementation of a variable at each iteration of the loop:

   i = 1
   while i <= 5:
       print(i**2)
       i = i + 1
   

3. The order of the values can be reversed by using a decrementation:

   i = 5
   while i > 0:
       print(i**2)
       i = i - 1
   

4. Summing the odd integers with a while loop reaches the same result without using the ** operator:

   i = 1
   n = 1
   while i < 10:
       print(n)
       i = i + 2
       n = n + i
   

5. A recursive function is another approach which has a certain similarity with the while loop:

   def f(i, n):
       if i < 10:
           print(n)
           f(i + 2, n + i + 2)
   
   f(1, 1)
   

6. Using the functional programming approach a solution in one line is possible:

   list(map(lambda i: print((i+1)**2), range(5)))
   

7. The previous approaches have the merit of a certain generality which the following solution lacks:

   print(1)
   print(4)
   print(9)
   print(16)
   print(25)
   

8. The results can be put in a CSV file and then displayed in a spreadsheet and a bar chart:

   # Create a CSV file containing the squares.
   
   with open('squares.csv', 'w') as f:
       f.write('N,N**2\n')
       for i in range(1, 6):
           f.write(str(i) + ',' + str(i**2) + '\n')
   
   # Display it as a spreadsheet.
   
   show_file('squares.csv')
   
   # Display it as a bar chart.
   
   chart(read_file('squares.csv'), mark='bar', x_type='ordinal')
   

9. The results could also be drawn using the turtle metaphor:

   # This program uses the turtle to draw the
   # numbers using 7 segments.
   
   from turtle import hop, lt, rt, fd, pensize
   
   dist = 20  # length of each segment
   
   segments = {  # the 7 segments of each symbol
       ' ':0,
       '0':63, '1':12,  '2':118, '3':94,  '4':77,
       '5':91, '6':123, '7':14,  '8':127, '9':95
   }
   
   def print_char(c):  # draw a symbol
       lt(90)
       hop(); fd(dist)
       bits = segments[c]  # each bit = 1 segment
       for i in range(7):
           if (bits & 1) == 0: hop()
           fd(dist)
           bits >>= 1
           if i != 2: rt(90)
       hop(); fd(dist)
       lt(90)
       hop(); fd(dist/2)
   
   def print(n):  # print a number
       for c in str(n):
           print_char(c)
       print_char(' ')
   
   hop(); fd(-175); pensize(5)
   
   for i in range(1, 6):  # compute the squares
       print(i**2)