O‘zbekiston respublikasi oliy va o‘rta maxsus ta’lim vazirligi muxammad al-xorazmiy nomidagi toshkent axborot texnologiyalari universiteti huzuridagi pedagog kadrlarni qayta tayyorlash va ularning malakasini oshirish tarmoq markazi

keys() metodi fayldagi barcha kalitlarni olib beradi, values() metodi esa kalitga tegishli bo‘lgan qiymatlarni qaytaradi:
with shelve.open(FILENAME) as states:
for city in states.keys():
print(city, end=" ")
# London Paris Berlin Madrid
print()
for country in states.values():
print(country, end="")
# Great Britain France Germany Spain
Yuqorida ko‘rib o‘tilgan metodlardan tashqari yana bir metod mavjud. Bu metod yordamida ma’lumotlarni turkumlar (kortejlar) ko‘rinishidagi to‘plam sifatida olish mumkin. Har bir kortej o‘zida kalit va qiymatni saqlaydi.
with shelve.open(FILENAME) as states:
for state in states.items():
print(state)
Konsol oynasidagi natija:
("London", "Great Britain")
("Paris", "France")
("Berlin", "Germany")
("Madrid", "Spain")
Ma’lumotlarni yangilash
Ma’lumotlarni o‘zgartirish uchun ko‘rsatilgan kalitga yangi qiymat berish, ma’lumotlarni kiritish uchun yangi kalit belgilash kifoya:
import shelve
FILENAME = "states2"
with shelve.open(FILENAME) as states:
states["London"] = "Great Britain"
states["Paris"] = "France"
states["Berlin"] = "Germany"
states["Madrid"] = "Spain"
with shelve.open(FILENAME) as states:
states["London"] = "United Kingdom"
states["Brussels"] = "Belgium"
for key in states:
print(key, " - ", states[key])


Ma’lumotlarni o‘chirish
Bir vaqtning o‘zida kalit va qiymatni o‘chirish uchun pop() funksiyasidan foylaniladi, agar kalit topilmasa ko‘rsatilgan qiymat o‘zgaruvchiga uzatiladi:
with shelve.open(FILENAME) as states:
state = states.pop("London", "NotFound")
print(state)
Shu bilan birga ma’lumotlarni o‘chirish uchun del operatoridan foydalanish mumkin:
with shelve.open(FILENAME) as states:
del states["Madrid"] # Madrid kalitli ma’lumotlni o‘chirish
Barcha elementlarni o‘chirish uchun clear() metodidan foydalaniladi:
with shelve.open(FILENAME) as states:
states.clear()