The syntax of "if" requires two elements, a
condition and an indented block of statements.
The indented block can have any number of
statements, which can be any sort of valid
Python statement, even including another "if"
statement. The code shown here is a function
to determine whether or not a number is odd
and has the number 6 somewhere in its decimal
representation. The indented block of the
first if starts with the definition of digits,
whereas the indented block of the *nested if*
is the `return True`

statement.

1 2 3 4 5 6 | ```
def oddsix(number):
if number%2 == 1:
digits = str(number)
if "6" in digits:
return True
return False
``` |

Instead of writing oddsix this way, an equivalent formulation would be this simple four-line function.

1 2 3 4 | ```
def oddsix(number):
if (number%2 == 1) and "6" in str(number):
return True
return False
``` |

Yet simpler is a two-line function:

1 2 | ```
def oddsix(number):
return (number%2 == 1) and "6" in str(number)
``` |