Functions

Question 1

Arguments

Answer 1

positional *args
keyword **kwargs
variable-length (varargs): *args, **kwargs
required
optional
actual parameters

Question 2

Parameters

Answer 2

(pos, /, pos_or_kw, *, kw)
pos and **kwargs can have same names
PEP 570
formal parameters

Question 3

Parameters order

Answer 3

non-default parameters, default parameters

Question 4

Arguments order

Answer 4

positional, keyword

Question 5

Lambda

Answer 5

bound variable
higher-order
single expression
no type annotations

Question 6

Global Scope

Answer 6

declared in the main body
available from any scope
global variable
global keyword
namespace of __main__ module
module scope

Question 7

Local Scope

Answer 7

declare inside function
available within the function

Question 8

Nonlocal Variables

Answer 8

nonlocal keyword
used in nested functions
variable belongs to the outer function
variable refers to the previously bound variable in the closest enclosing scope

Question 9

Enclosing Scope

Answer 9

scope of the outer function
local scope of any enclosing function’s local scopes
nonlocal scope

Question 10

Built-in Scope

Answer 10

special reserved keywords

Question 11

LEGB

Answer 11

Local
Enclosing
Global
Built-in

Question 12

First-Class Function

Answer 12

• assign to variable
• pass as an argument
• return from function

first-class citizen

Question 13

Higher-Order Function

Answer 13

a function that can take other functions as arguments or return functions as results

map, filter

Question 14

Free Variable

Answer 14

variable that is used in a code block but not defined there

Question 15

Closure

Answer 15

function that retains access to variables from the enclosing scope even after the outer function has finished executing

closure factory

Question 16

Decorator

Answer 16

def decorator(func):
    def wrapper(*args, **kwargs):
        ...
        result = func(*args, **kwargs)
        ...
        return result
    return wrapper

@functools.wraps(func)

Question 17

Pie-Decorator

Answer 17

@decorator
def func:
    ...

func = decorator(func)

Question 18

Decorator with optional arguments

Answer 18

def name(_func=None, *, key1=value1, key2=value2, ...):
    def decorator_name(func):
        ...
    if _func is None:
        return decorator_name
    else:
        return decorator_name(_func)

Question 19

Type Hints

Answer 19

def func(arg1: type1, arg2: type2 = default, ...) -> return_type:
    ...

mypy, pyright, typeguard