Functions and Modularity Flashcards

What will the following code print? ```python def add(a, b): return a + b result = add(b=3, a=7) print(result) ```

Answer: 10

Keyword arguments can be passed in any order; Python maps them by name, so a=7 and b=3 gives 10.

Which module provides the `wraps` decorator used to preserve a wrapped function's metadata?

Answer: functools

`functools.wraps` copies `__name__`, `__doc__`, and other attributes from the wrapped function to the wrapper.

What is the output? ```python def greet(name, msg='Hello'): return f'{msg}, {name}!' print(greet('Alice', msg='Hi')) ```

Answer: Hi, Alice!

Passing `msg='Hi'` overrides the default value 'Hello', so the function returns 'Hi, Alice!'.

What does a generator function use instead of `return` to yield values lazily?

Answer: yield

The `yield` statement pauses the function and returns a value to the caller, resuming on the next iteration.

How do you call a function stored in a variable `fn` with arguments unpacked from a list `args`?

Answer: fn(*args)

The `*` operator unpacks a list (or tuple) into positional arguments when calling a function.

What is the scope resolution order Python uses when looking up a variable name?

Answer: Local → Enclosing → Global → Built-in

Python follows LEGB: Local → Enclosing → Global → Built-in when resolving names.

What will this code output? ```python def make_adder(n): return lambda x: x + n add5 = make_adder(5) print(add5(3)) ```

Answer: 8

`make_adder(5)` returns a lambda that adds 5 to its argument; calling it with 3 returns 8.