{"id":1665,"date":"2025-09-30T22:41:55","date_gmt":"2025-09-30T15:41:55","guid":{"rendered":"https:\/\/kienthucmo.com\/?p=1665"},"modified":"2025-11-05T23:45:28","modified_gmt":"2025-11-05T16:45:28","slug":"sap-xep-phan-tu-trong-dictionary-voi-python","status":"publish","type":"post","link":"https:\/\/kienthucmo.com\/vi\/sap-xep-phan-tu-trong-dictionary-voi-python\/","title":{"rendered":"S\u1eafp x\u1ebfp c\u00e1c ph\u1ea7n t\u1eed trong Dictionary v\u1edbi Python"},"content":{"rendered":"\n

Dictionary (t\u1eeb \u0111i\u1ec3n) l\u00e0 m\u1ed9t trong nh\u1eefng c\u1ea5u tr\u00fac d\u1eef li\u1ec7u c\u01a1 b\u1ea3n v\u00e0 c\u1ef1c k\u1ef3 h\u1eefu \u00edch trong Python \u2014 l\u01b0u tr\u1eef d\u1eef li\u1ec7u theo c\u1eb7p key: value<\/code>, tra c\u1ee9u nhanh theo key v\u00e0 r\u1ea5t thu\u1eadn ti\u1ec7n \u0111\u1ec3 bi\u1ec3u di\u1ec5n c\u00e1c b\u1ea3ng tra c\u1ee9u, c\u1ea5u h\u00ecnh, th\u1ed1ng k\u00ea… T\u1eeb Python 3.7 tr\u1edf \u0111i, dict<\/code> gi\u1eef th\u1ee9 t\u1ef1 ch\u00e8n (insertion order), nh\u01b0ng vi\u1ec7c s\u1eafp x\u1ebfp theo m\u1ed9t ti\u00eau ch\u00ed c\u1ee5 th\u1ec3 (theo key, theo value, theo nhi\u1ec1u ti\u00eau ch\u00ed, ho\u1eb7c theo gi\u00e1 tr\u1ecb trong dictionary l\u1ed3ng nhau)<\/strong> v\u1eabn l\u00e0 nhu c\u1ea7u r\u1ea5t th\u01b0\u1eddng g\u1eb7p khi m\u00ecnh c\u1ea7n hi\u1ec3n th\u1ecb d\u1eef li\u1ec7u g\u1ecdn g\u00e0ng, x\u1ebfp h\u1ea1ng, l\u1ea5y top N, ho\u1eb7c xu\u1ea5t b\u00e1o c\u00e1o.<\/p>\n\n\n\n

Trong b\u00e0i vi\u1ebft n\u00e0y, h\u00e3y c\u00f9ng m\u00ecnh hi\u1ec3u nh\u1eefng c\u00e1ch s\u1eafp x\u1ebfp dictionary <\/strong>, so s\u00e1nh hi\u1ec7u n\u0103ng, c\u0169ng nh\u01b0 nh\u1eefng tr\u01b0\u1eddng h\u1ee3p \u00e1p d\u1ee5ng. B\u1eaft \u0111\u1ea7u th\u00f4i n\u00e0o…!!!<\/p>\n\n\n\n

1. Khi n\u00e0o c\u1ea7n s\u1eafp x\u1ebfp dict<\/code><\/h2>\n\n\n\n

M\u00ecnh t\u00f3m t\u1eaft m\u1ed9t v\u00e0i t\u00ecnh hu\u1ed1ng th\u1ef1c t\u1ebf:<\/p>\n\n\n\n

    \n
  • Hi\u1ec3n th\u1ecb cho ng\u01b0\u1eddi d\u00f9ng<\/strong>: danh b\u1ea1, b\u1ea3ng b\u00e1o c\u00e1o t\u00e0i ch\u00ednh, b\u1ea3ng th\u1ed1ng k\u00ea \u2014 tr\u00ecnh t\u1ef1 theo t\u00ean, theo m\u00e3, ho\u1eb7c theo gi\u00e1 tr\u1ecb (v\u00ed d\u1ee5: doanh thu).<\/li>\n\n\n\n
  • X\u1ebfp h\u1ea1ng \/ top N<\/strong>: v\u00ed d\u1ee5 th\u1ed1ng k\u00ea view c\u1ee7a c\u00e1c trang, m\u00ecnh mu\u1ed1n top 5 trang \u0111\u01b0\u1ee3c xem nhi\u1ec1u nh\u1ea5t.<\/li>\n\n\n\n
  • So s\u00e1nh \/ \u0111\u1ed3ng b\u1ed9 d\u1eef li\u1ec7u<\/strong>: khi c\u1ea7n so s\u00e1nh hai ngu\u1ed3n, s\u1eafp x\u1ebfp gi\u00fap so s\u00e1nh d\u1ec5 \u0111\u1ecdc.<\/li>\n\n\n\n
  • D\u1eef li\u1ec7u l\u1ed3ng nhau<\/strong>: mu\u1ed1n s\u1eafp x\u1ebfp theo m\u1ed9t thu\u1ed9c t\u00ednh trong gi\u00e1 tr\u1ecb (v\u00ed d\u1ee5: student['score']<\/code>).<\/li>\n\n\n\n
  • Xu\u1ea5t file c\u00f3 th\u1ee9 t\u1ef1 c\u1ed1 \u0111\u1ecbnh<\/strong>: CSV\/JSON c\u1ea7n th\u1ee9 t\u1ef1 nh\u1ea5t \u0111\u1ecbnh cho ng\u01b0\u1eddi \u0111\u1ecdc.<\/li>\n<\/ul>\n\n\n\n

    N\u1ebfu kh\u00f4ng thu\u1ed9c nh\u1eefng tr\u01b0\u1eddng h\u1ee3p tr\u00ean, vi\u1ec7c gi\u1eef insertion order (m\u1eb7c \u0111\u1ecbnh) c\u00f3 th\u1ec3 \u0111\u00e3 \u0111\u1ee7. Nh\u01b0ng th\u1ef1c t\u1ebf \u1ee9ng d\u1ee5ng th\u01b0\u1eddng r\u01a1i v\u00e0o nh\u1eefng t\u00ecnh hu\u1ed1ng m\u00ecnh li\u1ec7t k\u00ea.<\/p>\n\n\n\n

    2. Dictionary trong Python v\u00e0 \u0111\u1eb7c \u0111i\u1ec3m c\u1ea7n l\u01b0u \u00fd<\/h2>\n\n\n\n

    M\u1ed9t s\u1ed1 \u0111i\u1ec3m c\u1ea7n nh\u1edb tr\u01b0\u1edbc khi s\u1eafp x\u1ebfp:<\/p>\n\n\n\n

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    • dict<\/code> l\u00e0 c\u1ea5u tr\u00fac key \u2192 value; key ph\u1ea3i l\u00e0 immutable<\/strong> (v\u00ed d\u1ee5: str, int, tuple).<\/li>\n\n\n\n
    • Python 3.7+ gi\u1eef th\u1ee9 t\u1ef1 ch\u00e8n<\/strong>, nh\u01b0ng \u0111\u00f3 kh\u00f4ng ph\u1ea3i l\u00e0 \u201cs\u1eafp x\u1ebfp\u201d; n\u00f3 ch\u1ec9 gi\u1eef th\u1ee9 t\u1ef1 b\u1ea1n th\u00eam ph\u1ea7n t\u1eed.<\/li>\n\n\n\n
    • sorted()<\/code> lu\u00f4n tr\u1ea3 v\u1ec1 m\u1ed9t danh s\u00e1ch<\/strong> (list) \u2014 th\u01b0\u1eddng l\u00e0 list c\u00e1c tuple (key, value)<\/code>. N\u1ebfu mu\u1ed1n dict \u0111\u00e3 s\u1eafp x\u1ebfp, c\u1ea7n chuy\u1ec3n l\u1ea1i b\u1eb1ng dict()<\/code> ho\u1eb7c collections.OrderedDict<\/code> (cho t\u01b0\u01a1ng th\u00edch ng\u01b0\u1ee3c).<\/li>\n\n\n\n
    • Vi\u1ec7c s\u1eafp x\u1ebfp t\u1ed1n O(n log n) (Timsort), n\u00ean c\u00e2n nh\u1eafc tr\u00ean d\u1eef li\u1ec7u l\u1edbn.<\/li>\n<\/ul>\n\n\n\n

      3. C\u00e1c ph\u01b0\u01a1ng ph\u00e1p c\u01a1 b\u1ea3n \u0111\u1ec3 s\u1eafp x\u1ebfp Dictionary<\/h2>\n\n\n\n

      C\u0103n b\u1ea3n nh\u1ea5t l\u00e0 d\u00f9ng sorted()<\/code> tr\u00ean dict.items()<\/code>.<\/p>\n\n\n\n

      V\u00ed d\u1ee5 c\u01a1 b\u1ea3n \u2014 s\u1eafp x\u1ebfp students<\/code> theo t\u00ean (m\u1eb7c \u0111\u1ecbnh sorted()<\/code> tr\u00ean items s\u1ebd so s\u00e1nh theo key tr\u01b0\u1edbc):<\/p>\n\n\n\n

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