Boshqaruv oqimi: shartlar, sikllar va pattern matching

ball = 78
 
if ball >= 90:
    baho = "A"
elif ball >= 75:
    baho = "B"
elif ball >= 60:
    baho = "C"
else:
    baho = "F"
 
print(baho)   # B

if 0 <= x < 10:          # 0 <= x and x < 10 bilan bir xil
    ...
if a == b == c:          # uchalasi teng
    ...

holat = "kattalar" if yosh >= 18 else "bolalar"

if yosh >= 18 and hujjat_bor:
    ...
if is_admin or is_owner:
    ...
if not ruxsat:
    ...

if lst and lst[0] > 0:        # lst bo'sh bo'lsa, lst[0] chaqirilmaydi — IndexError yo'q
    ...
if user is not None and user.is_active:
    ...

>>> 0 or "standart"
'standart'          # birinchi truthy qiymat
>>> "" or None or []
[]                  # hammasi falsy — oxirgisi qaytadi
>>> 5 and "salom"
'salom'             # hammasi truthy — oxirgisi
>>> 0 and "salom"
0                   # birinchi falsy

mevalar = ["olma", "nok", "uzum"]
for meva in mevalar:
    print(meva)
 
for harf in "salom":
    print(harf)

range(5)          # 0, 1, 2, 3, 4
range(2, 6)       # 2, 3, 4, 5
range(0, 10, 3)   # 0, 3, 6, 9
range(5, 0, -1)   # 5, 4, 3, 2, 1

# ❌ C uslubi — ko'proq kod, ko'proq xato ehtimoli
for i in range(len(mevalar)):
    print(i, mevalar[i])
 
# ✅ Pythonic
for i, meva in enumerate(mevalar):
    print(i, meva)
 
for i, meva in enumerate(mevalar, start=1):   # 1 dan sanash
    print(f"{i}. {meva}")

ismlar = ["Ali", "Vali", "Gani"]
ballar = [85, 92, 78]
 
for ism, ball in zip(ismlar, ballar):
    print(f"{ism}: {ball}")

for pred, label in zip(predictions, labels, strict=True):   # uzunlik farq qilsa — ValueError
    ...

narxlar = {"olma": 12000, "nok": 15000}
 
for meva in narxlar:                    # kalitlar
    ...
for narx in narxlar.values():           # qiymatlar
    ...
for meva, narx in narxlar.items():      # juftliklar — eng ko'p ishlatiladi
    print(f"{meva}: {narx:,} so'm")

for x in reversed(lst):         # teskari (nusxa yaratmaydi)
    ...
for x in sorted(lst):           # saralangan (yangi ro'yxat)
    ...
for ism in sorted(ballar, key=ballar.get, reverse=True):   # lug'atni qiymat bo'yicha
    ...

sonlar = [1, 2, 3, 4, 5, 6]
for x in sonlar:
    if x % 2 == 0:
        sonlar.remove(x)        # XAVFLI: indekslar siljiydi, ba'zi elementlar o'tkazib yuboriladi

sonlar = [x for x in sonlar if x % 2 != 0]

urinish = 0
while urinish < 3:
    javob = input("Parol: ")
    if javob == "maxfiy":
        print("Kirdingiz")
        break
    urinish += 1
else:
    print("Urinishlar tugadi")

import random
import time
 
 
def call_with_retry(fn, max_attempts: int = 5):
    delay = 1.0
    attempt = 1
    while True:
        try:
            return fn()
        except ConnectionError:
            if attempt == max_attempts:
                raise                      # urinishlar tugadi — xatoni yuqoriga uzatamiz
            sleep_for = delay + random.uniform(0, delay)   # jitter — hamma bir vaqtda qayta urinmasin
            print(f"{attempt}-urinish muvaffaqiyatsiz, {sleep_for:.1f}s kutamiz")
            time.sleep(sleep_for)
            delay *= 2                     # 1, 2, 4, 8...
            attempt += 1

i = 0
while i < 10:
    print(i)
    # i += 1 unutildi → cheksiz sikl. Ctrl+C bilan to'xtating.

for qator in fayl_qatorlari:
    qator = qator.strip()
    if not qator or qator.startswith("#"):
        continue                    # bo'sh va izoh qatorlarini o'tkazib yuborish
    qayta_ishlash(qator)

def birinchi_tub_bo_luvchi(n: int) -> int | None:
    for d in range(2, int(n ** 0.5) + 1):
        if n % d == 0:
            break
    else:
        return None     # sikl break'siz tugadi → bo'luvchi topilmadi, n tub
    return d
 
print(birinchi_tub_bo_luvchi(91))   # 7
print(birinchi_tub_bo_luvchi(97))   # None

def http_status(code: int) -> str:
    match code:
        case 200 | 201:
            return "OK"
        case 400:
            return "Noto'g'ri so'rov"
        case 401 | 403:
            return "Ruxsat yo'q"
        case 429:
            return "Juda ko'p so'rov — kuting"
        case _:                           # qolgan hammasi (default)
            return "Noma'lum"

def render(block: dict) -> str:
    match block:
        case {"type": "text", "text": str(matn)}:
            return matn
        case {"type": "tool_use", "name": nom, "input": dict(args)}:
            return f"[asbob chaqirildi: {nom}({', '.join(args)})]"
        case {"type": "image", "source": {"media_type": mt}}:
            return f"[rasm: {mt}]"
        case {"type": tip}:
            return f"[noma'lum blok: {tip}]"
        case _:
            raise ValueError(f"Blok emas: {block!r}")
 
 
print(render({"type": "text", "text": "Salom!"}))
print(render({"type": "tool_use", "name": "get_weather", "input": {"city": "Toshkent", "unit": "C"}}))
print(render({"type": "image", "source": {"media_type": "image/png", "data": "..."}}))

Salom!
[asbob chaqirildi: get_weather(city, unit)]
[rasm: image/png]

def buyruq(qator: str) -> str:
    match qator.split():
        case ["chiq"] | ["exit"]:
            return "Xayr!"
        case ["salom", ism]:
            return f"Salom, {ism}!"
        case ["qo'sh", *sonlar] if all(s.isdigit() for s in sonlar):
            return str(sum(int(s) for s in sonlar))
        case ["qo'sh", *_]:
            return "Faqat sonlarni qo'shaman"
        case []:
            return ""
        case _:
            return "Tushunmadim"
 
 
print(buyruq("salom Aziz"))    # Salom, Aziz!
print(buyruq("qo'sh 2 3 5"))   # 10
print(buyruq("qo'sh 2 uch"))   # Faqat sonlarni qo'shaman

# Walrus'siz:
qator = f.readline()
while qator:
    qayta_ishlash(qator)
    qator = f.readline()
 
# Walrus bilan:
while (qator := f.readline()):
    qayta_ishlash(qator)

import re
 
if (m := re.search(r"(\d+) ta", matn)) is not None:
    soni = int(m.group(1))

def keyinroq_yozaman():
    pass          # yoki ...
 
class MaxsusXato(Exception):
    pass
 
if shart:
    ...           # Ellipsis — "bu yer hali tayyor emas" ma'nosida ko'p ishlatiladi

def javob_ber(xabar: str) -> str:
    match xabar.lower().split():
        case []:
            return "Biror narsa yozing."
        case ["salom", *_] | ["assalomu", *_]:
            return "Va alaykum assalom! Qanday yordam bera olaman?"
        case [*_, "narx"] | [*_, "narxi"]:
            return "Narxlar haqida ma'lumot uchun /narxlar buyrug'ini yozing."
        case _:
            return "Kechirasiz, tushunmadim. Boshqacha yozib ko'ring."
 
 
def main() -> None:
    print("Chatbot. Chiqish uchun 'chiq' deb yozing.")
    tarix: list[tuple[str, str]] = []
    while True:
        try:
            xabar = input("Siz: ").strip()
        except (EOFError, KeyboardInterrupt):    # Ctrl+D / Ctrl+C
            print()
            break
        if xabar.lower() in {"chiq", "exit", "quit"}:
            break
        javob = javob_ber(xabar)
        tarix.append((xabar, javob))
        print(f"Bot: {javob}")
 
    print(f"Suhbat tugadi. {len(tarix)} ta xabar almashildi.")
 
 
if __name__ == "__main__":
    main()