sbs5@kangaroo:~/cs370/www/lectures$ date
Wed Feb 12 02:29:35 PM EST 2025
sbs5@kangaroo:~/cs370/www/lectures$ pwd
/home/accts/sbs5/cs370/www/lectures
sbs5@kangaroo:~/cs370/www/lectures$ p
Python 3.10.12 (main, Jan 17 2025, 14:35:34) [GCC 11.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import time
from timeit import *
from functools import wraps
>>> >>> >>> def slow_square(number):
    ''' Take a nap and then print the square of a number.'''
    print(f"Sleeping for {number} seconds")
    time.sleep(number)
    return number**2
... ... ... ... ... 
>>> slow_square(3)
Sleeping for 3 seconds
9
>>> from functools import lru_cache
lru_cache
>>> <function lru_cache at 0x77e3f6be9cf0>
>>> slow_square = lru_cache(slow_square)
>>> slow_square(3)
Sleeping for 3 seconds
9
>>> slow_square(3)
9
>>> slow_square(4)
Sleeping for 4 seconds
16
>>> slow_square(4)
16
>>> @lru_cache
def slow_square(number):
    ''' Take a nap and then print the square of a number.'''
    print(f"Now sleeping for {number} seconds")
    time.sleep(number)
    return number**2
... ... ... ... ... ... 
>>> slow_square(3)
Now sleeping for 3 seconds
9
>>> slow_square(3)
9
>>> @lru_cache
def slow_add(a,b):
    ''' Take a nap and then add two numbers.'''
    print(f"Sleeping for {a+b} seconds")
    time.sleep(a+b)
    return a+b
... ... ... ... ... ... 
>>> slow_add(3 5)
  File "<stdin>", line 1
    slow_add(3 5)
             ^^^
SyntaxError: invalid syntax. Perhaps you forgot a comma?
>>> slow_add(3, 5)
Sleeping for 8 seconds
8
>>> slow_add(3, 5)
8
>>> slow_add(5,3))
  File "<stdin>", line 1
    slow_add(5,3))
                 ^
SyntaxError: unmatched ')'
>>> slow_add(5,3)
Sleeping for 8 seconds
8
>>> slow_add(5,3)
8
>>> dir(slow_add)
['__annotations__', '__call__', '__class__', '__copy__', '__deepcopy__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__get__', '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__name__', '__ne__', '__new__', '__qualname__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__wrapped__', 'cache_clear', 'cache_info', 'cache_parameters']
>>> slow_add.__name__
'slow_add'
>>> slow_add.__doc__
' Take a nap and then add two numbers.'
>>> slow_add.__wrapped__
<function slow_add at 0x77e3f6afe320>
>>> def bold(func):
    def g(*args):
        print ("<b>", end="")
        func(*args)
        print ("</b>", end="")
    return g 
... ... ... ... ... ... 
>>> def italic(func):
    def g(*args):
        print ("<i>", end="")
        func(*args)
        print ("</i>", end="")
    return g 
... ... ... ... ... ... 
>>> 
>>> test("this is a string.")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'test' is not defined
>>> @bold
@italic
def test(s):
    'this is test'
    print (str(s), end="")
... ... ... ... ... 
>>> test("this is a string.")
<b><i>this is a string.</i></b>>>> test
<function bold.<locals>.g at 0x77e3f57e64d0>
>>> test.__name__
'g'
>>> test.__doc__
>>> test.__wrapped__
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'function' object has no attribute '__wrapped__'
>>> def debug(f):
    def g(*args):
        print ("Calling: {} with args: {}".format(f.__name__, args))
        val = f(*args)
        print ("Exiting: {} with value: {}".format(f.__name__, val))
        return val
    return g 
... ... ... ... ... ... ... \
... 0
  File "<stdin>", line 9
    0
    ^
SyntaxError: invalid syntax
>>> @debug
def add2(a):
    return a + 2
... ... ... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'debug' is not defined
>>> def debug(f):
    def g(*args):
        print ("Calling: {} with args: {}".format(f.__name__, args))
        val = f(*args)
        print ("Exiting: {} with value: {}".format(f.__name__, val))
        return val
    return g
... ... ... ... ... ... ... @debug
def add2(a):
    return a + 2
  File "<stdin>", line 8
    @debug
    ^
SyntaxError: invalid syntax
>>> ... ... 
>>> @debug
def add2(a):
    return a + 2
... ... ... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'debug' is not defined
>>> def debug(f):
    def g(*args):
        print ("Calling: {} with args: {}".format(f.__name__, args))
        val = f(*args)
        print ("Exiting: {} with value: {}".format(f.__name__, val))
        return val
    return g 
... ... ... ... ... ... ... 
>>> @debug
def add2(a):
    return a + 2
... ... ... 
>>> add2(8)
Calling: add2 with args: (8,)
Exiting: add2 with value: 10
10
>>> (8)
8
>>> (8,)
(8,)
>>> def trace(f):
    f.indent = 0
    def g(x):
        print('|  ' * f.indent + '|--', f.__name__, x)
        f.indent += 1
        value = f(x)
        print('|  ' * f.indent + '|--', 'return', repr(value))
        f.indent -= 1
        return value
    return g
... ... ... ... ... ... ... ... ... ... 
>>> @trace
def fib(n):
    if n == 0:
        return 1
    elif n == 1:
        return 1
    else:
        return fib(n - 1) + fib(n - 2)
... ... ... ... ... ... ... ... 
>>> fib(4)
|-- fib 4
|  |-- fib 3
|  |  |-- fib 2
|  |  |  |-- fib 1
|  |  |  |  |-- return 1
|  |  |  |-- fib 0
|  |  |  |  |-- return 1
|  |  |  |-- return 2
|  |  |-- fib 1
|  |  |  |-- return 1
|  |  |-- return 3
|  |-- fib 2
|  |  |-- fib 1
|  |  |  |-- return 1
|  |  |-- fib 0
|  |  |  |-- return 1
|  |  |-- return 2
|  |-- return 5
5
>>> def memofib(n):
    table = [False for x in range(n+1)]
    return memofibaux(n,table)

def memofibaux(n, table):
    if table[n]: return table[n]
    if n <= 1: return 1
    else:
        table[n] = memofibaux(n-1, table) + memofibaux(n-2, table)
        return table[n]
... ... ... >>> ... ... ... ... ... ... 
>>> memofib(10)
89
>>> memofib(5)
8
>>> def trace2(f):  
    f.indent = 0
    def g(*x):
        print('|  ' * f.indent + '|--', f.__name__, x)
        f.indent += 1
        value = f(*x)
        print('|  ' * f.indent + '|--', 'return', repr(value))
        f.indent -= 1
        return value
    return g
... ... ... ... ... ... ... ... ... ... 
>>> @trace2
def memofibaux(n, table):
    if table[n]: return table[n]
    if n <= 1: return 1
    else:
        table[n] = memofibaux(n-1, table) + memofibaux(n-2, table)
        return table[n]@trace2
def memofibaux(n, table):
    if table[n]: return table[n]
    if n <= 1: return 1
    else:
        table[n] = memofibaux(n-1, table) + memofibaux(n-2, table)
        return table[n]
... ... ... ... ... ... ...   File "<stdin>", line 8
    def memofibaux(n, table):
    ^^^
SyntaxError: invalid syntax
>>>   File "<stdin>", line 1
    if table[n]: return table[n]
IndentationError: unexpected indent
>>>   File "<stdin>", line 1
    if n <= 1: return 1
IndentationError: unexpected indent
>>>   File "<stdin>", line 1
    else:
IndentationError: unexpected indent
>>>   File "<stdin>", line 1
    table[n] = memofibaux(n-1, table) + memofibaux(n-2, table)
IndentationError: unexpected indent
>>>   File "<stdin>", line 1
    return table[n]
IndentationError: unexpected indent
>>> 
>>> @trace2
def memofibaux(n, table):
    if table[n]: return table[n]
    if n <= 1: return 1
    else:
        table[n] = memofibaux(n-1, table) + memofibaux(n-2, table)
        return table[n]
... ... ... ... ... ... ... 
>>> memofib(5)
|-- memofibaux (5, [False, False, False, False, False, False])
|  |-- memofibaux (4, [False, False, False, False, False, False])
|  |  |-- memofibaux (3, [False, False, False, False, False, False])
|  |  |  |-- memofibaux (2, [False, False, False, False, False, False])
|  |  |  |  |-- memofibaux (1, [False, False, False, False, False, False])
|  |  |  |  |  |-- return 1
|  |  |  |  |-- memofibaux (0, [False, False, False, False, False, False])
|  |  |  |  |  |-- return 1
|  |  |  |  |-- return 2
|  |  |  |-- memofibaux (1, [False, False, 2, False, False, False])
|  |  |  |  |-- return 1
|  |  |  |-- return 3
|  |  |-- memofibaux (2, [False, False, 2, 3, False, False])
|  |  |  |-- return 2
|  |  |-- return 5
|  |-- memofibaux (3, [False, False, 2, 3, 5, False])
|  |  |-- return 3
|  |-- return 8
8
>>> memofib(5)
|-- memofibaux (5, [False, False, False, False, False, False])
|  |-- memofibaux (4, [False, False, False, False, False, False])
|  |  |-- memofibaux (3, [False, False, False, False, False, False])
|  |  |  |-- memofibaux (2, [False, False, False, False, False, False])
|  |  |  |  |-- memofibaux (1, [False, False, False, False, False, False])
|  |  |  |  |  |-- return 1
|  |  |  |  |-- memofibaux (0, [False, False, False, False, False, False])
|  |  |  |  |  |-- return 1
|  |  |  |  |-- return 2
|  |  |  |-- memofibaux (1, [False, False, 2, False, False, False])
|  |  |  |  |-- return 1
|  |  |  |-- return 3
|  |  |-- memofibaux (2, [False, False, 2, 3, False, False])
|  |  |  |-- return 2
|  |  |-- return 5
|  |-- memofibaux (3, [False, False, 2, 3, 5, False])
|  |  |-- return 3
|  |-- return 8
8
>>> 
sbs5@kangaroo:~/cs370/www/lectures$ exit

Process shell finished