{"id":1661,"date":"2025-09-30T20:10:38","date_gmt":"2025-09-30T13:10:38","guid":{"rendered":"https:\/\/kienthucmo.com\/?p=1661"},"modified":"2025-11-05T23:44:57","modified_gmt":"2025-11-05T16:44:57","slug":"xoa-phan-tu-trong-dictionary-voi-python","status":"publish","type":"post","link":"https:\/\/kienthucmo.com\/vi\/xoa-phan-tu-trong-dictionary-voi-python\/","title":{"rendered":"X\u00f3a ph\u1ea7n t\u1eed trong Dictionary v\u1edbi Python"},"content":{"rendered":"\n

Trong Python, dictionary<\/code> (dict) l\u00e0 c\u1ea5u tr\u00fac d\u1eef li\u1ec7u r\u1ea5t ph\u1ed5 bi\u1ebfn \u0111\u1ec3 l\u01b0u tr\u1eef c\u1eb7p key \u2014 value<\/em>. Khi x\u1eed l\u00fd d\u1eef li\u1ec7u th\u1eadt, m\u00ecnh th\u01b0\u1eddng ph\u1ea3i th\u00eam, s\u1eeda, v\u00e0 \u0111\u1eb7c bi\u1ec7t l\u00e0 x\u00f3a<\/strong> ph\u1ea7n t\u1eed trong dictionary \u2014 \u0111\u1ec3 l\u00e0m s\u1ea1ch d\u1eef li\u1ec7u, l\u1ecdc th\u00f4ng tin, ho\u1eb7c chu\u1ea9n b\u1ecb d\u1eef li\u1ec7u cho b\u01b0\u1edbc x\u1eed l\u00fd ti\u1ebfp theo. B\u00e0i vi\u1ebft n\u00e0y m\u00ecnh c\u00f9ng b\u1ea1n s\u1ebd t\u00ecm hi\u1ec3u chi ti\u1ebft c\u00e1c c\u00e1ch x\u00f3a ph\u1ea7n t\u1eed trong dictionary b\u1eb1ng Python: c\u00fa ph\u00e1p, v\u00ed d\u1ee5 th\u1ef1c t\u1ebf, l\u01b0u \u00fd khi l\u1ed7i x\u1ea3y ra v\u00e0 so s\u00e1nh hi\u1ec7u n\u0103ng \u0111\u1ec3 ch\u00fang ta c\u00f3 th\u1ec3 ch\u1ecdn ph\u01b0\u01a1ng ph\u00e1p ph\u00f9 h\u1ee3p.<\/p>\n\n\n\n

1. T\u1ed5ng quan v\u1ec1 Dictionary trong Python<\/h2>\n\n\n\n

dictionary<\/code> l\u00e0 m\u1ed9t c\u1ea5u tr\u00fac \u00e1nh x\u1ea1 (mapping) l\u01b0u tr\u1eef theo c\u1eb7p key: value<\/code>. M\u1ed9t s\u1ed1 \u0111i\u1ec3m c\u01a1 b\u1ea3n c\u1ea7n nh\u1edb tr\u01b0\u1edbc khi thao t\u00e1c x\u00f3a:<\/p>\n\n\n\n

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  • Key ph\u1ea3i l\u00e0 ki\u1ec3u hashable (v\u00ed d\u1ee5: str<\/code>, int<\/code>, tuple<\/code> immutable), v\u00e0 m\u1ed7i key l\u00e0 duy nh\u1ea5t trong m\u1ed9t dict.<\/li>\n\n\n\n
  • Gi\u00e1 tr\u1ecb (value) c\u00f3 th\u1ec3 l\u00e0 b\u1ea5t k\u1ef3 ki\u1ec3u d\u1eef li\u1ec7u n\u00e0o (mutable ho\u1eb7c immutable).<\/li>\n\n\n\n
  • T\u1eeb Python 3.7 tr\u1edf \u0111i, dict gi\u1eef th\u1ee9 t\u1ef1 ch\u00e8n (insertion order), n\u00ean thao t\u00e1c nh\u01b0 popitem()<\/code> s\u1ebd x\u00f3a ph\u1ea7n t\u1eed cu\u1ed1i c\u00f9ng ch\u00e8n v\u00e0o.<\/li>\n\n\n\n
  • Thao t\u00e1c x\u00f3a th\u01b0\u1eddng c\u00f3 \u0111\u1ed9 ph\u1ee9c t\u1ea1p trung b\u00ecnh O(1)<\/strong> tr\u00ean m\u1ed7i ph\u1ea7n t\u1eed, nh\u01b0ng c\u1ea7n l\u01b0u \u00fd khi thao t\u00e1c l\u1eb7p x\u00f3a nhi\u1ec1u ph\u1ea7n t\u1eed \u2014 chi\u1ebfn l\u01b0\u1ee3c t\u1ed1t s\u1ebd kh\u00e1c nhau t\u00f9y m\u1ee5c \u0111\u00edch.<\/li>\n<\/ul>\n\n\n\n

    M\u1ee5c ti\u00eau c\u1ee7a ph\u1ea7n n\u00e0y: n\u1eafm c\u00e1c c\u01a1 ch\u1ebf x\u00f3a kh\u00e1c nhau \u0111\u1ec3 bi\u1ebft khi n\u00e0o d\u00f9ng del<\/code>, pop()<\/code>, popitem()<\/code>, clear()<\/code> ho\u1eb7c t\u1ea1o dict m\u1edbi b\u1eb1ng comprehension.<\/p>\n\n\n\n

    2. S\u1eed d\u1ee5ng t\u1eeb kh\u00f3a del<\/code> \u0111\u1ec3 x\u00f3a ph\u1ea7n t\u1eed<\/h2>\n\n\n\n

    C\u00fa ph\u00e1p c\u01a1 b\u1ea3n:<\/p>\n\n\n\n

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