return statement return statement is used within the body of function to indicate that the function should immediately cease executionand that an expressed value should be returned to the caller if return statement is executed without an explicit argumentthe none value is automatically returned likewisenone will be returned if the flow of control ever reaches the end of function body without having executed return statement oftena return statement will be the final command within the body of the functionas was the case in our earlier example of count function howeverthere can be multiple return statements in the same functionwith conditional logic controlling which such command is executedif any as further exampleconsider the following function that tests if value exists in sequence def contains(datatarget)for item in targetif item =targetreturn true return false found match if the conditional within the loop body is ever satisfiedthe return true statement is executed and the function immediately endswith true designating that the target value was found converselyif the for loop reaches its conclusion without ever finding the matchthe final return false statement will be executed information passing to be successful programmerone must have clear understanding of the mechanism in which programming language passes information to and from function in the context of function signaturethe identifiers used to describe the expected parameters are known as formal parametersand the objects sent by the caller when invoking the function are the actual parameters parameter passing in python follows the semantics of the standard assignment statement when function is invokedeach identifier that serves as formal parameter is assignedin the function' local scopeto the respective actual parameter that is provided by the caller of the function for exampleconsider the following call to our count function from page prizes count(gradesa just before the function body is executedthe actual parametersgrades and are implicitly assigned to the formal parametersdata and targetas followsdata grades target