Function annotations - ignored by Python itself, but other tools could use it for something.

Simple Example #

def someFunction(thing: str):
  ...

^ This indicates that the argument should be string.

Return #

Can specify return type

def someFunction(thing: str) -> str:
  ...

^ This specifies the output should be a string.

Resources #

• PEP-3107: Function Annotations

• https://stackoverflow.com/questions/54962869/function-parameter-with-colon