13. for statement

The for statement allows us to repeat a block of code several times while a variable is changing its value.

This block of code that is repeated several times is called a loop.

Example:

for num in range(1, 10):
    print(num)

This example will print to the screen all the numbers from 1 to 9 (10 is not included in the range).

Example:

for nombre in ['Abel', 'Beatriz', 'Conchi', 'Diana', 'Elena', 'Francisco']:
    print('Hola', nombre)

This example will print a greeting for all the names in the list, from 'Abel' to 'Elena'.

Exercises

  1. Write a program that prints the table of 6:

    6 x 0 = 0
6 x 1 = 6
6 x 2 = 12
6 x 3 = 18
6 x 4 = 24
6 x 5 = 30
6 x 6 = 36
6 x 7 = 42
6 x 8 = 48
6 x 9 = 54
6 x 10 = 60

    Clue:

    for ...
    print('6 x', b, '=', 6*b)

  2. Write a program that asks for a number and then adds all the numbers between 1 and the entered number.

    Example 1:

    Introduce un número: 5
La suma de todos los números desde
el 1 hasta el 5 es igual a 15

    Example 2:

    Introduce un número: 27
La suma de todos los números desde
el 1 hasta el 27 es igual a 378

    Clue:

    suma = 0

for i in ...
    suma = suma + i

print('La suma de todos los números desde')
print('el 1 hasta el', ... ,'es igual a', ... )

  3. Write a program that asks for a number and then multiplies all the numbers between 1 and the entered number. This operation is called factorial.

    Example 1:

    Introduce un número: 3
El factorial de 3 es igual a 6

    Example 2:

    Introduce un número: 10
El factorial de 10 es igual a 3628800

  4. Write a program that prints on the screen all the ages from 10 to 20 and, next to it, that prints if it is older or younger:

    10 años, menor de edad
11 años, menor de edad
12 años, menor de edad
13 años, menor de edad
14 años, menor de edad
15 años, menor de edad
16 años, menor de edad
17 años, menor de edad
18 años, mayor de edad
19 años, mayor de edad
20 años, mayor de edad

  5. Write a program that asks for a number and then prints if it is divisible by any number between 2 and 20.

    Example 1:

    Introduce un número: 60

60 es divisible por 2
60 es divisible por 3
60 es divisible por 4
60 es divisible por 5
60 es divisible por 6
60 es divisible por 10
60 es divisible por 12
60 es divisible por 15
60 es divisible por 20

    Example 2:

    Introduce un número: 28

28 es divisible por 2
28 es divisible por 4
28 es divisible por 7
28 es divisible por 14

    Note that a number 'num' is divisible by 5 if its remainder when divided by 5 equals zero:

    if (num % 5 == 0):
    print(num, ' es divisible por ', 5)

  6. Write a program that prints all the numbers from 1 to 100. Numbers divisible by 3 must be replaced by the word 'choco'. Numbers divisible by 5 must be replaced by the word 'late'. Numbers divisible by 3 and 5 must be replaced by the word 'chocolate':

    1
2
choco
4
late
choco
7
8
choco
late
11
choco
13
14
chocolate
16
.
.
.

    Note that a number 'num' is divisible by 3 if its remainder when divided by 3 equals zero:

    if (num % 3 == 0):
    print(num, ' es divisible por 3')