Advanced Python

Python-ga chuqurroq sho'ng'ing va kodlash mahoratingizni oshiring.

Python generatori:

• Iterator obyektini qaytaruvchi funksiyaning maxsus turi.
• Qo'ng'iroq qiluvchi tomonidan so'ralganda birma-bir qiymatlar ketma-ketligini ishlab chiqaradi.
• Generatorlar ijroni to'xtatib turish va ketma-ketlikda keyingi qiymatni qaytarish uchun "yield" kalit so'zi yordamida aniqlanadi.
• Bu xotiradan yanada samarali foydalanish imkonini beradi va cheksiz ketma-ketlikni yaratishi mumkin.

''' Iterator'''importtimedefanswer():
result= []
time.sleep(3)
result.append(14)
time.sleep(3)
result.append(44)
time.sleep(3)
result.append(75)
returnresultforxinanswer():
print(x)

'''Generator'''importtimedefanswer():
time.sleep(3)
yield14time.sleep(3)
yield44time.sleep(3)
yield75forxinanswer():
print(x)

1677122996544.gif.mp4

'''Generator range()'''importtime# def answer():# while True:# time.sleep(3)# yield 75### for x in answer():# print(x * x)defreverse(nums: list):
n=len(nums)
forxinrange(n-1, -1, -1):
yieldnums[x]
# for x in reverse([1, 2, 3]):# print(x)# print(list(reverse([1, 2, 3])))iterator=iter(reverse([1, 2, 3, 4, 5]))
whileTrue:
try:
n=next(iterator)
exceptStopIteration:
breakprint(n)
forrinreverse([1, 2, 3, 4, 5]):
print(r)
forxinrange(100000000): # range() generatortime.sleep(1)
print(x)

Decorator

Dekoratorlar yuqori darajadagi funktsiyalarni chaqirish uchun oddiy sintaksisni ta'minlaydi. Ta'rifga ko'ra, dekorator boshqa funktsiyani qabul qiladigan va ikkinchi funktsiyaning harakatini aniq o'zgartirmasdankengaytiradigan funktsiyadir.Bu chalkash tuyuladi, lekin aslida unday emas, ayniqsa dekorativlar qanday ishlashiga oid bir nechta misollarni ko'rganingizdan keyin. Ushbu maqoladagi barcha misollarni bu erda topishingiz mumkin.

defhello(name):
# ichki funksiyadefget_name():
returnf"Hello, {name}!"# ichki funksiyani qaytarishreturnget_namehello_func=hello("Sarvar")
print(hello_func())

Decorator funksiya argument sifatida funksiya qabul qiladi.

defmake_decorator(func):
definner():
# Ichki funksiya orqali func xususiyatlarini o'zgartirishimiz mumkinprint("Dekorator ishlayapti")
func()
# Ichki funksiya qaytariladireturninnerdefmy_func():
print("Dekorator uchun ishlatiladigan funksiya")
decorated_func=make_decorator(my_func)
decorated_func()
# Dekorator ishlayapti# Dekorator uchun ishlatiladigan funksiya

Bitta funksiyada bir nechta decorator ishlatishimiz ham mumkin, bunda birinchisidan boshlab decoratorlar ishlab keladi.

defdivide_decorator(func):
defdivide_inner(a, b):
try:
returnfunc(a, b)
exceptZeroDivisionError:
print("Nolga bo'lish mumkin emas!")
returndivide_innerdefsecond_zero(func): # zero 0 - > 1 functiondefinner(a, b):
ifb==0:
b+=1returnfunc(a, b)
returninner@second_zero@divide_decoratordefdivider(a, b):
returna/bprint(divider(10, 5)) # 2.0print(divider(10, 0)) # 10.0

'''Decorator'''importtime# def add(a, b):# return a + b### # print(add.__call__(1, 2))# # print(add(1, 2))### def calc(func, a, b):# return func(a, b)### result = calc(add, 1, 4)# print(result)# def adder(n):# def inner(m):# return 5 + m# return inner### add_5 = adder(5)# def func():# def another_func():# return 1# return another_func## print(func()())# def do():# started = time.time()# print(started)# time.sleep(3)# print("done")# finished = time.time()# print(finished)# print(f"took {finished - started} seconds")### do()# def do1():# started = time.time()# print(started)# time.sleep(3)# print("done")# finished = time.time()# print(finished)# print(f"took {finished - started} seconds")### do1()# def timer(func):# started = time.time()# func()# fnished = time.time()# print(f"took {fnished - started} seconds")## timer(do())# timer(do2())# not called# def timer(func):# def inner():# started = time.time()# func()# fnished = time.time()# print(f"took {fnished - started} seconds")## return inner### # do = timer(do())# # do2 timer(do2())## do()# do2()# @timer# def dos():# time.sleep(3)# print("done")# def star(func):# def inner():# print("*" * 12)# func()# print("*" * 12)## return inner# def presnet(func):# def inner():# print("%" * 12)# func()# print("%" * 12)## return inner## @star# @presnet# def hello():# print("Hello World")### hello()# def wrap(char):# def wrapper(func):# def inner():# print(char * 12)# func()# print(char * 12)## return inner## return wrapper### @wrap("%")# @wrap("*")# def hello():# print("Hello World")### hello()'''log nomli dekorator yarating, u qaysi funksiya qachon chaqirilganini va qachon funksiya tugagani vaqtnini ekranga chiqarsin. Vaqtni formatlashni https://strftime.org/ saytidan ko'rishingiz mumkin.Misol:@logdef hello(): print("hello")hello()Output:- called function: hello at 8:43:35hello- finished function: hello at 8:43:36'''

Context Mangers

'''Context Managers'''# with open('file.txt', 'w') as file:# file.write("Hello")## file = open('file,txt', 'w')# file.write('All Nc')# file.close()# class FileOpener:# def __init__(self, filename, mode='r'):# self.filename = filename,# self.mode = mode# self.opened_file = None## def __enter__(self):# print("Entered")# return 1## def __exit__(self, exc_type, exc_val, exc_tb):# print('Exited')### with FileOpener('file,txt', 'w') as file:# print('file', file)# print('nima_dir boldi')# class FileOpener:# def __init__(self, filename, mode='r'):# self.filename = filename# self.mode = mode# self.opened_file = None## def __enter__(self):# print("Entered")# self.opened_file = open(self.filename, self.mode)# return self.opened_file## def __exit__(self, exc_type, exc_val, exc_tb):# print('Exited')# if self.opened_file:# self.opened_file.close()### with FileOpener('file.txt', 'w') as file:# print('file', file)# file.write('All Nc')# raise Exception# print('nima_dir boldi')fromcontextlibimportcontextmanager@contextmanagerdeffile_opener(filename, mode):
file=open(filename, mode)
print('open file')
try:
yieldfilefinally:
file.close()
print('closed file')
withfile_opener('files.txt', 'w') asfile:
print('file', file)
raiseException'''log nomli kontekst meneger yarating, u qaysi kontext qachon ochilganini va qachon kontext yopilganini vaqtnini ekranga chiqarsin.Misol:with log(): print("hello")Output:- context manager opened at 8:43:35hello- context manager closed at 8:43:36'''

Typing modul

Asosiy turlar

• int: Butun son
• float: O'nli son
• bool: Mantiqiy qiymat (True/False)
• str: Matn

Ro'yxatlar va Lug'atlar

• List[int]: Butun sonlardan iborat ro'yxat
• Dict[str, int]: Kalitlari matn, qiymatlari butun son bo'lgan lug'at

Union

O'zgaruvchining bir nechta turda bo'lishi mumkinligini belgilash uchun Union dan foydalaniladi.

fromtypingimportUniondeffoo(x: Union[int, str]) ->None:
print(x)

Optional

O'zgaruvchi ma'lum bir turda yoki None bo'lishi mumkinligini belgilash uchun Optional dan foydalaniladi.

fromtypingimportOptionaldeffoo(x: Optional[int]) ->None:
print(x)

Tuple

Aniq uzunlikdagi va ma'lum turlardagi elementlardan iborat tuple belgilash uchun Tuple dan foydalaniladi.

fromtypingimportTupledeffoo(x: Tuple[int, float, str]) ->None:
print(x)

Any

Har qanday turdagi bo'lishi mumkin bo'lgan o'zgaruvchi belgilash uchun Any dan foydalaniladi.

fromtypingimportAnydeffoo(x: Any) ->None:
print(x)

Type Aliases

Murakkab turlarni o'qilishi osonroq qilish uchun tur ta'riflari ishlatilishi mumkin.

fromtypingimportListVector=List[float]
deffoo(v: Vector) ->None:
print(v)

Misol

fromtypingimportList, Dict, Union, Optionaldefprocess_data(data: List[Dict[str, Union[int, float]]]) ->Optional[float]:
ifnotdata:
returnNonereturnsum(item['value'] foritemindata) /len(data)

Xulosa

typing moduli Python kodlaringizni tushunarliroq, qulayroq va xatolarni kamaytirish uchun juda foydali. Bu modul bilan yozilgan kodlar kelajakdagi o'zgarishlar uchun yanada aniqroq tuzilmani ta'minlaydi.

Unpacking and packing

Unpacking va packing - Python dasturlash tilida juda foydali texnikalar bo‘lib, ular ob’ektlarni ochish va yig‘ish jarayonlarini osonlashtiradi.

Unpacking

Unpacking ob’ektni bir necha qismlarga ajratish va har bir qismni alohida o‘zgaruvchiga tayinlash imkonini beradi. Bu ko‘pincha ro‘yxatlar va tuple (to‘plam)lar bilan ishlatiladi.

Tuple bilan unpacking

my_tuple= (1, 2, 3)
a, b, c=my_tupleprint(a) # 1print(b) # 2print(c) # 3

Ro'yxat bilan unpacking

my_list= [4, 5, 6]
x, y, z=my_listprint(x) # 4print(y) # 5print(z) # 6

Funksiya chaqirilishi natijasini unpacking qilish

defget_coordinates():
return (50.4501, 30.5234)
lat, lon=get_coordinates()
print(f"Latitude: {lat}, Longitude: {lon}")

Packing

Packing esa aksincha, bir nechta qiymatlarni bitta tuple yoki ro‘yxatga yig‘ish imkonini beradi.

Tuple bilan packing

a, b, c=1, 2, 3my_tuple= (a, b, c)
print(my_tuple) # (1, 2, 3)

Ro'yxat bilan packing

x, y, z=4, 5, 6my_list= [x, y, z]
print(my_list) # [4, 5, 6]

Funksiya orqali packing

defcreate_point(x, y, z):
return (x, y, z)
point=create_point(7, 8, 9)
print(point) # (7, 8, 9)

*args va **kwargs bilan ishlash

Unpacking va packing ko‘pincha *args va **kwargs bilan birgalikda ishlatiladi.

- *args funksiyaga kiritilgan argumentlarni tuple ko‘rinishida qabul qiladi,

- **kwargs esa kalit-qiymat juftliklarini dictionary ko‘rinishida qabul qiladi.

defmy_function(*args, **kwargs):
print(args)
print(kwargs)
my_function(1, 2, 3, name="Alice", age=30)
# (1, 2, 3)# {'name': 'Alice', 'age': 30}

Unpacking va packingni birgalikda ishlatish

defcalculate_sum(a, b, c):
returna+b+cmy_numbers= [1, 2, 3]
result=calculate_sum(*my_numbers)
print(result) # 6# **kwargs bilan unpacking # noqadefprint_info(name, age):
print(f"Name: {name}, Age: {age}")
info= {"name": "Alice", "age": 30}
print_info(**info)
# Name: Alice, Age: 30

Python'da hashable va unhashable tushunchalari muhim ahamiyatga ega, ayniqsa, ma'lumotlar tuzilmalari va lug'atlar bilan ishlashda.

Hashable (Hashlanadigan)

• Hashable obyektlar - bu o'zlarining hash() qiymatiga ega bo'lgan obyektlar. Bu qiymat doimiy bo'lib, obyektning umri davomida o'zgarmaydi. Hashable obyektlarni lug'at (dictionary) kalitlari yoki set elementlari sifatida ishlatish mumkin.

Hashable obyektlar:

1. Integer (int)
2. Float (float)
3. String (str)
4. Tuple (tuple), agar uning ichidagi barcha elementlar ham hashable bo'lsa
5. Frozen set (frozenset) Misol:

hash(42) # Integer hashablehash("hello") # String hashablehash((1, 2, 3)) # Tuple hashable

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Unhashable (Hashlanmaydigan)

• Unhashable obyektlar - bu o'zlarining hash() qiymatiga ega bo'lmagan obyektlar. Bunday obyektlarni lug'at kalitlari yoki set elementlari sifatida ishlatib bo'lmaydi, chunki ular mutable (o'zgartirilishi mumkin) va ularning qiymatlari o'zgarishi mumkin.

Unhashable obyektlar:

1. List (list)
2. Dictionary (dict)
3. Set (set)
4. Tuple (tuple), agar uning ichidagi biror element unhashable bo'lsa Misol:

hash([1, 2, 3]) # List unhashablehash({1: "one", 2: "two"}) # Dictionary unhashablehash({1, 2, 3}) # Set unhashable

Nima uchun bu muhim?

Hashable obyektlar ma'lumotlar tuzilmalarida, ayniqsa lug'atlar va setlarda, samarali indekslash va izlashni ta'minlaydi. Unhashable obyektlar esa o'zgaruvchan bo'lgani uchun ularni kalit yoki element sifatida ishlatish xavfli, chunki bu obyektlar o'zgarganda hash qiymati ham o'zgaradi va noto'g'ri xatti-harakatlar yuzaga kelishi mumkin.

• Yaxshi dasturlash amaliyotlaridan biri sifatida, kalit yoki set elementi sifatida hashable obyektlarni tanlash kerak, bu esa kodingizni ishonchli va samarali qiladi.

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Django'da select_related va prefetch_related optimizatsiya metodlari bo'lib, ular ORM (Object-Relational Mapping) so'rovlarining samaradorligini oshirish uchun ishlatiladi.

• Ular har xil turdagi ma'lumotlar bazasi so'rovlarini oldindan yuklab olish orqali so'rovlar sonini kamaytiradi, bu esa bajarilish vaqtini tezlashtiradi.

select_related

Nimani ishlatadi: select_related odatda ForeignKey yoki OneToOneField maydonlar bilan ishlatiladi. Qanday ishlaydi: Bu metod bog'langan modelni JOIN operatori yordamida bitta so'rovda oladi. Bu esa bog'liq bo'lgan ma'lumotlarni olish uchun kerak bo'ladigan alohida so'rovlar sonini kamaytiradi. Qachon ishlatish kerak: Agar sizda ForeignKey yoki OneToOneField bilan bog'langan ma'lumotlar mavjud bo'lsa va siz ularga tez-tez murojaat qilmoqchi bo'lsangiz, select_relatedni ishlatishingiz kerak. Misol:

Model example

classAuthor(models.Model):
name=models.CharField(max_length=100)
classBook(models.Model):
title=models.CharField(max_length=100)
author=models.ForeignKey(Author, on_delete=models.CASCADE)
# Query with select_relatedbooks=Book.objects.select_related('author').all()
forbookinbooks:
print(book.author.name) # Author ma'lumotlari bitta JOIN so'rovda keladi

prefetch_related

Nimani ishlatadi: prefetch_related ManyToManyField yoki ForeignKey maydonlar uchun ishlatiladi, lekin u select_relateddan farqli o'laroq, so'rovlarni ikkita alohida so'rov sifatida yuboradi, keyin esa natijalarni Python tarafida bog'laydi. Qanday ishlaydi: U bog'langan ob'ektlarni alohida so'rovda yuklab oladi va asosiy so'rov bilan natijalarni bog'laydi. Bu katta hajmdagi bog'langan ob'ektlar mavjud bo'lgan holatlarda yaxshi ishlaydi. Qachon ishlatish kerak: Agar sizda ManyToMany yoki katta hajmdagi ForeignKey bog'lanishlar mavjud bo'lsa, prefetch_relatedni ishlatish samarali bo'ladi. Misol:

Model example

classBook(models.Model):
title=models.CharField(max_length=100)
authors=models.ManyToManyField(Author)
#Query with prefetch_relatedbooks=Book.objects.prefetch_related('authors').all()
forbookinbooks:
forauthorinbook.authors.all():
print(author.name) # Authors alohida so'rovda yuklab olinadi

Xulosa

• select_related bir-to-bir yoki bir-to-ko'p bog'lanishlar uchun optimal va bitta so'rovda ma'lumotlarni olib keladi.
• prefetch_related ko'p-to-ko'p bog'lanishlar yoki katta hajmdagi bog'langan ob'ektlar uchun ishlatiladi va so'rovlar sonini kamaytiradi, lekin ularni alohida-alohida bajaradi.

Python Queue Example

importqueueimportthreadingimporttime# Telegram botiga yuborilayotgan buyruqlar navbati (queue)command_queue=queue.Queue()
# Bu funksiya botga kelayotgan buyruqlarni navbatga qo'shadidefadd_command_to_queue(command):
print(f"Buyruq qo'shildi: {command}")
command_queue.put(command)
# Bu funksiya navbatdagi buyruqlarni ketma-ket bajaradidefprocess_commands():
whileTrue:
# Navbatdan buyruqni olishcommand=command_queue.get()
ifcommandisNone:
breakprint(f"Buyruqni bajarish: {command}")
time.sleep(2) # Buyruqni bajarishga sarflanadigan vaqtcommand_queue.task_done()
print(f"Buyruq bajarildi: {command}")
# Buyruqlarni qabul qilish uchun yangi threadingthreading.Thread(target=process_commands, daemon=True).start()
# Botga kelayotgan buyruqlaradd_command_to_queue("/start")
add_command_to_queue("/help")
add_command_to_queue("/settings")
# Buyruqlar navbatda bajarilguncha kutishcommand_queue.join()
print("Barcha buyruqlar bajarildi!")```