Kod nr 1
old_list = [[1, 2, 3], [4, 5, 6], [7, 8, 'a']]
new_list = old_list
new_list[2][2] = 9
print('Old List:', old_list)
print('ID of Old List:', id(old_list))
print('New List:', new_list)
print('ID of New List:', id(new_list))Kod nr 2
import copy
old_list = [[1, 1, 1], [2, 2, 2], [3, 3, 3]]
new_list = copy.copy(old_list)
old_list.append([4, 4, 4])
print("Old list:", old_list)
print("New list:", new_list)Kod nr 3
import copy
old_list = [[1, 2, 3], [4, 5, 6], [7, 8, 'a']]
new_list = copy.copy(old_list)
new_list[2][2] = 9
print('Old List:', old_list)
print('ID of Old List:', id(old_list))
print('New List:', new_list)
print('ID of New List:', id(new_list))Kod nr 4
import copy
old_list = [[1, 2, 3], [4, 5, 6], [7, 8, 'a']]
new_list = copy.deepcopy(old_list)
new_list[2][2] = 9
print('Old List:', old_list)
print('ID of Old List:', id(old_list))
print('New List:', new_list)
print('ID of New List:', id(new_list))
Kod 4b
import copy
class Person:
def __init__(self, age, name):
self.age = age
self.name = name
p1 = Person(20, "Jan")
p2 = copy.copy(p1)
print(id(p1))
print(id(p1.name))
print(id(p2))
print(id(p2.name))
p1.name = "Anna"
print(id(p1.name))
print(id(p2.name))Kod nr 4c
import copy
class Person:
def __init__(self, age, name, children):
self.age = age
self.name = name
self.children = children
p1 = Person(20, "Jan", ["Anna","Krzysztof"])
p2 = copy.copy(p1)
print(id(p1))
print(id(p1.children))
print(id(p2))
print(id(p2.children))
p1.children[1] = "Tomasz"
print(id(p1.children))
print(id(p2.children))
Kod nr 4d
import copy
class Person:
def __init__(self, age, name, children):
self.age = age
self.name = name
self.children = children
p1 = Person(20, "Jan", ["Anna","Krzysztof"])
p2 = copy.deepcopy(p1)
print(id(p1))
print(id(p1.children))
print(id(p2))
print(id(p2.children))
p1.children[1] = "Tomasz"
print(id(p1.children))
print(id(p2.children))
Kod nr 4e
import copy
class Person:
def __init__(self, age, name, children):
self.age = age
self.name = name
self.children = children
def __copy__(self):
return Person(self.age, self.name, self.children.copy())
def __deepcopy__(self, memodict = {}):
return Person(self.age, self.name[:-1][:-1], self.children.copy())
p1 = Person(20, "Jan", ["Anna","Krzysztof"])
p2 = copy.copy(p1)
print(id(p1) == id(p2))
print(id(p1.age) == id(p2.age))
print(id(p1.name) == id(p2.name))
print(id(p1.children) == id(p2.children))
p3 = copy.deepcopy(p1)
print(id(p1) == id(p3))
print(id(p1.age) == id(p3.age))
print(id(p1.name) == id(p3.name))
print(id(p1.children) == id(p3.children))
https://www.pythonforthelab.com/blog/deep-and-shallow-copies-of-objects/
Dokumentacja https://docs.python.org/3/tutorial/errors.html
Kodn nr 5
10 * (1/0)
4 + spam*3
'2' + 2Kod nr 6
while True:
try:
x = int(input("Please enter a number: "))
break
except ValueError:
print("Oops! That was no valid number. Try again...")
print("number", x)
Kod nr 7
try:
raise Exception('spam', 'eggs')
except Exception as inst:
print(type(inst)) # the exception instance
print(inst.args) # arguments stored in .args
print(inst) # __str__ allows args to be printed directly,
# but may be overridden in exception subclasses
x, y = inst.args # unpack args
print('x =', x)
print('y =', y)Kod nr 8
class B(Exception):
pass
class C(B):
pass
class D(C):
pass
for cls in [B, C, D]:
try:
raise cls()
except D:
print("D")
except C:
print("C")
except B:
print("B")Kod nr 9
def this_fails():
x = 1/0
try:
this_fails()
except ZeroDivisionError as err:
print('Handling run-time error:', err)Kod nr 10
try:
raise NameError('HiThere')
except NameError:
print('An exception flew by!')
raiseKod nr 11
try:
raise KeyboardInterrupt
finally:
print('Goodbye, world!')Kod nr 12
def divide(x, y):
try:
result = x / y
except ZeroDivisionError:
print("division by zero!")
else:
print("result is", result)
finally:
print("executing finally clause")
divide(2, 1)
divide(2, 0)
divide("2", "1")Ćwiczenie. Stwórz klasę Calculator i dodaj w niej kilka
metod (bez __) symulujących operacje arytmetyczne. Zabezpiecz działanie
przed wykrzucaniem błędów.
Dekoratory to pewien “sposób” na wykonywanie funkcji na funkcjach.
kod nr 13
def shout(text):
return text.upper()
print(shout('Hello'))
yell = shout
print(yell('Hello'))
kod nr 14
def up(text):
return text.upper()
def down(text):
return text.lower()
def greet(func):
test = func("abcXYZ")
print(test)
greet(up)
greet(down)kod nr 15
def create_adder(x):
def adder(y):
return x + y
return adder
add_15 = create_adder(15)
print(add_15(10))kod nr 16
def hello_decorator(func):
def inner1():
print("Hello, this is before function execution")
func()
print("This is after function execution")
return inner1
def function_to_be_used():
print("This is inside the function !!")
function_to_be_used = hello_decorator(function_to_be_used)
function_to_be_used()kod nr 17
def hello_decorator(func):
def inner1(*args, **kwargs):
print("before Execution")
returned_value = func(*args, **kwargs)
print("after Execution")
return returned_value
return inner1
@hello_decorator
def sum_two_numbers(a, b):
print("Inside the function")
return a + b
a, b = 1, 2
print("Sum =", sum_two_numbers(a, b))kod nr 18
def decor1(func):
def inner():
x = func()
return x * x
return inner
def decor(func):
def inner():
x = func()
return 2 * x
return inner
@decor1
@decor
def num():
return 10
print(num())Kod nr 18 jest równoważny decor1(decor(num))
Dekoratory z parametrem
kod nr 19
@decorator(params)
def func_name():
''' Function implementation'''jest równoważny
kod nr 20
def func_name():
''' Function implementation'''
func_name = (decorator(params))(func_name)kod nr 21
def decorator_fun(func):
print("Inside decorator")
def inner(*args, **kwargs):
print("Inside inner function")
print("Decorated the function")
func()
return inner
@decorator_fun
def func_to():
print("Inside actual function")
func_to()kod nr 22
def decorator_fun(func):
print("Inside decorator")
def inner(*args, **kwargs):
print("Inside inner function")
print("Decorated the function")
func()
return inner
def func_to():
print("Inside actual function")
decorator_fun(func_to)()Praktyczne zastosowanie
kod nr 23
import functools
import time
def timer(func):
@functools.wraps(func)
def wrapper_timer(*args, **kwargs):
start_time = time.perf_counter() # 1
value = func(*args, **kwargs)
end_time = time.perf_counter() # 2
run_time = end_time - start_time # 3
print(f"Finished {func.__name__!r} in {run_time:.4f} secs")
return value
return wrapper_timer
@timer
def waste_some_time(num_times):
for _ in range(num_times):
sum([i**2 for i in range(10000)])
waste_some_time(5)kod nr 24
import functools
def debug(func):
@functools.wraps(func)
def wrapper_debug(*args, **kwargs):
args_repr = [repr(a) for a in args] # 1
kwargs_repr = [f"{k}={v!r}" for k, v in kwargs.items()] # 2
signature = ", ".join(args_repr + kwargs_repr) # 3
print(f"Calling {func.__name__}({signature})")
value = func(*args, **kwargs)
print(f"{func.__name__!r} returned {value!r}") # 4
return value
return wrapper_debug
@debug
def silnia(n):
if n == 0 or n == 1:
return 1
return n * silnia(n - 1)
print(silnia(7))
kod nr 25
import functools
import math
def debug(func):
@functools.wraps(func)
def wrapper_debug(*args, **kwargs):
args_repr = [repr(a) for a in args] # 1
kwargs_repr = [f"{k}={v!r}" for k, v in kwargs.items()] # 2
signature = ", ".join(args_repr + kwargs_repr) # 3
print(f"Calling {func.__name__}({signature})")
value = func(*args, **kwargs)
print(f"{func.__name__!r} returned {value!r}") # 4
return value
return wrapper_debug
math.factorial = debug(math.factorial)
def approximate_e(terms=18):
return sum(1 / math.factorial(n) for n in range(terms))
print(approximate_e(10))
Kod nr 26
class Point:
def __init__(self, x, y):
self.__x = x
self.__y = y
def get_x(self):
return self.__x
def set_x(self, value):
self.__x = value
def get_y(self):
return self.__y
def set_y(self, value):
self.__y = value
point = Point(12, 5)
print(point.get_x())
print(point.get_y())
point.set_x(42)
print(point.get_x())
# print(point.__x)
Kod nr 27
class Point:
def __init__(self, x, y):
self.x = x
self.y = y
point = Point(12, 5)
print(point.x)
Kod nr 28
class Circle:
def __init__(self, radius):
self.__radius = radius
def _get_radius(self):
print("Get radius")
return self.__radius
def _set_radius(self, value):
print("Set radius")
self.__radius = value
def _del_radius(self):
print("Delete radius")
del self.__radius
radius = property(
fget=_get_radius,
fset=_set_radius,
fdel=_del_radius,
doc="The radius property."
)
circle = Circle(42.0)
print(circle.radius)
circle.radius = 100.0
print(circle.radius)
del circle.radius
# print(circle.radius)
help(circle)
Kod nr 29
class Point:
def __init__(self, x, y):
self.__x = x
self.__y = y
def get_x(self):
return self.__x
def set_x(self, value):
self.__x = value
def get_y(self):
return self.__y
def set_y(self, value):
self.__y = value
x = property(get_x, set_x)
point = Point(12, 5)
print(point.get_x())
print(point.x)
point.x = 22
print(point.get_x())
Kod nr 30
class Circle:
def __init__(self, radius):
self.__radius = radius
@property
def radius(self):
"""The radius property."""
print("Get radius")
return self.__radius
@radius.setter
def radius(self, value):
print("Set radius")
self.__radius = value
@radius.deleter
def radius(self):
print("Delete radius")
del self.__radius
circle = Circle(42.0)
print(circle.radius)
circle.radius = 100.0
print(circle.radius)
del circle.radius
# print(circle.radius)
help(circle)
Kod nr 31
class Point:
def __init__(self, x, y):
self.__x = x
self.__y = y
@property
def x(self):
return self.__x
@property
def y(self):
return self.__y
point = Point(12, 5)
print(point.x)
# point.x = 3
Kod nr 32
class WriteCoordinateError(Exception):
pass
class Point:
def __init__(self, x, y):
self._x = x
self._y = y
@property
def x(self):
return self._x
@x.setter
def x(self, value):
raise WriteCoordinateError("x coordinate is read-only")
@property
def y(self):
return self._y
@y.setter
def y(self, value):
raise WriteCoordinateError("y coordinate is read-only")
point = Point(12, 5)
print(point.x)
point.x = 3
Kod nr 33
class Circle:
def __init__(self, radius):
self.radius = radius
@property
def radius(self):
return self._radius
@radius.setter
def radius(self, value):
self._radius = float(value)
@property
def diameter(self):
return self.radius * 2
@diameter.setter
def diameter(self, value):
self.radius = value / 2
circle = Circle(42)
print(circle.radius)
print(circle.diameter)
circle.diameter = 100
print(circle.radius)
print(circle.diameter)
Kod nr 34
class Circle:
def __init__(self, radius):
self.radius = radius
@property
def radius(self):
raise AttributeError("Radius is write-only")
@radius.setter
def radius(self, value):
self._radius = float(value)
circle = Circle(42)
# print(circle.radius)
circle.radius = 100