In coding, you often use branching. A branch in code is executed conditionally. Without branching, you only have a list of instructions and it would always do the same, no matter what happens.
Python does not have a trailing if statement.
In Python there these two kinds of ifs:
- if statements
if condition: statement if condition: code_block
- if expression (python > 2.5)
expression_if_true if condition else expression_if_false
You can check your Python version with
So you can do the following if expression:
a = False print("hello" if a else "world")
You can change the variable a to see the difference. It will return "hello" or "world" depending on the value of a.
An if-expression must always be an if-else expression, the following will throw an error because else is missing:
a = False print("hello" if a)
Returns if you run it:
python example.py File "example.py", line 4 print("hello" if a) ^ SyntaxError: invalid syntax
So the else for the if-expression in mandatory.