Functions

Question 1

Functions are objects

Answer 1

Python’s functions are first-class objects. You can assign them to variables, store them in data structures, pass them as arguments to other
functions, and even return them as values from other functions

Question 2

Assign function to variable

Answer 2

Becuase functions are objects they can be assigned to another varibale
~~~
def speak():
return “woof”

bark = speak
bark() <– returns “woof”
~~~

Question 3

Deleting fucntion

Answer 3

Function objects and their names are two separate concerns.
You can delete the function’s original name (speak). Since another name (bark) still points to the underlying function, you can still call the function through it:

>>> del speak
>>> speak()
NameError: "name 'speak' is not defined"
>>> bark()
'woof'

Question 4

Function name identifier

Answer 4

 bark.\_\_ name \_\_
'yell'

Python attaches a string identifier to every function at
creation time for debugging purposes. You can access this internal
identifier with the __name__ attribute

while the function’s __name__ is still “yell,” that doesn’t affect
how you can access the function object from your code. The name
identifier is merely a debugging aid. A variable pointing to a function
and the function itself are really two separate concerns.

Question 5

Function stored in DS

Answer 5

funcs = [bark, str.lower, str.capitalize]
>>> for f in funcs:
... print(f, f('hey there'))

Question 6

Function passed to fucntion

Answer 6

def greet(func):
greeting = func('Hi, I am a Python program')
print(greeting)

func can be any function
maybe we want to upercase

def upper(txt):
    return txt.upper()
		
greet(upper)
'HI, I AM A PYTHON PROGRAM!'

Question 7

Nested functions

Answer 7

Python allows functions to be defined inside
other functions. These are often called nested functions or inner functions. Here’s an example:
~~~
def speak(text):
def whisper(t):
return t.lower() + ‘…’
return whisper(text)

> > > speak(‘Hello, World’)
‘hello, world…’
~~~

Question 8

Functions Can Capture Local State

Answer 8

these inner functions
can also capture and carry some of the parent function’s state with them

lexical closures (or just closures, for
short). A closure remembers the values from its enclosing lexical scope even when the program flow is no longer in that scope.