if-elif-else statement

The code block after the first true condition of an if or elif statement is executed. If none of the conditions are true, the code block after the else is executed:

 1>>> x = 1
 2>>> if x < 1:
 3...     x = 2
 4...     y = 3
 5... elif x > 1:
 6...     x = 4
 7...     y = 5
 8... else:
 9...     x = 6
10...     y = 7
11...
12>>> print(x, y)
136 7
Lines 5 and 8

The elif and else clauses are optional, and there can be any number of elif clauses.

Lines 3, 4, 6, 7, 9 and 10

Python uses indentations to delimit blocks. No explicit delimiters such as brackets or curly braces are required. Each block consists of one or more statements separated by line breaks. All these statements must be on the same indentation level.