{"id":428,"date":"2025-03-21T03:56:31","date_gmt":"2025-03-21T03:56:31","guid":{"rendered":"https:\/\/news.techjunior.vn\/?p=428"},"modified":"2025-03-21T03:56:32","modified_gmt":"2025-03-21T03:56:32","slug":"%f0%9f%9a%80-lambda-function-trong-python-ham-an-danh-cuc-ky-tien-loi-%f0%9f%90%8d","status":"publish","type":"post","link":"https:\/\/news.techjunior.vn\/?p=428","title":{"rendered":"\ud83d\ude80 LAMBDA FUNCTION TRONG PYTHON \u2013 H\u00c0M \u1ea8N DANH C\u1ef0C K\u1ef2 TI\u1ec6N L\u1ee2I! \ud83d\udc0d"},"content":{"rendered":"
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\"\"<\/figure>\n<\/div>\n\n\n

Lambda function<\/strong> l\u00e0 m\u1ed9t trong nh\u1eefng t\u00ednh n\u0103ng \u0111\u1ed9c \u0111\u00e1o v\u00e0 m\u1ea1nh m\u1ebd c\u1ee7a Python, cho ph\u00e9p b\u1ea1n t\u1ea1o nhanh m\u1ed9t h\u00e0m ch\u1ec9 trong m\u1ed9t d\u00f2ng code. \u0110\u00e2y l\u00e0 c\u00f4ng c\u1ee5 c\u1ef1c k\u1ef3 h\u1eefu \u00edch khi b\u1ea1n mu\u1ed1n vi\u1ebft code ng\u1eafn g\u1ecdn, t\u1ed1i \u01b0u h\u00f3a hi\u1ec7u su\u1ea5t v\u00e0 l\u00e0m vi\u1ec7c v\u1edbi c\u00e1c h\u00e0m b\u1eadc cao nh\u01b0 map()<\/code>, filter()<\/code>, sorted()<\/code>, v\u00e0 reduce()<\/code>.<\/p>\n\n\n\n

Trong b\u00e0i vi\u1ebft n\u00e0y, ch\u00fang ta s\u1ebd \u0111i th\u1eadt chi ti\u1ebft<\/strong>, kh\u00e1m ph\u00e1 t\u1ea5t c\u1ea3 c\u00e1c kh\u00eda c\u1ea1nh c\u1ee7a lambda function<\/strong>, t\u1eeb c\u00fa ph\u00e1p, c\u00e1ch ho\u1ea1t \u0111\u1ed9ng, so s\u00e1nh v\u1edbi h\u00e0m th\u00f4ng th\u01b0\u1eddng, \u0111\u1ebfn c\u00e1c \u1ee9ng d\u1ee5ng th\u1ef1c t\u1ebf<\/strong> trong l\u1eadp tr\u00ecnh.<\/p>\n\n\n\n

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\ud83d\udccc 1. Lambda Function l\u00e0 g\u00ec?<\/strong><\/h2>\n\n\n\n

\ud83d\udd39 \u0110\u1ecbnh ngh\u0129a<\/strong><\/h3>\n\n\n\n

Lambda function l\u00e0 m\u1ed9t h\u00e0m \u1ea9n danh<\/strong> (kh\u00f4ng c\u00f3 t\u00ean) trong Python, \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 vi\u1ebft nh\u1eefng h\u00e0m \u0111\u01a1n gi\u1ea3n trong m\u1ed9t d\u00f2ng duy nh\u1ea5t.<\/p>\n\n\n\n

\ud83d\udd39 C\u00fa ph\u00e1p:<\/strong><\/p>\n\n\n\n

lambda arguments: expression\n<\/code><\/pre>\n\n\n\n
    \n
  • arguments<\/code>: Danh s\u00e1ch tham s\u1ed1 truy\u1ec1n v\u00e0o h\u00e0m.<\/li>\n\n\n\n
  • expression<\/code>: M\u1ed9t bi\u1ec3u th\u1ee9c duy nh\u1ea5t s\u1ebd \u0111\u01b0\u1ee3c th\u1ef1c thi v\u00e0 tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3.<\/li>\n<\/ul>\n\n\n\n
    \ud83d\udd39 \u0110\u1eb7c \u0111i\u1ec3m:<\/strong>
    \u2705 Kh\u00f4ng c\u1ea7n t\u1eeb kh\u00f3a def<\/code> v\u00e0 t\u00ean h\u00e0m.
    \u2705 Ch\u1ec9 ch\u1ee9a m\u1ed9t bi\u1ec3u th\u1ee9c duy nh\u1ea5t (kh\u00f4ng th\u1ec3 c\u00f3 nhi\u1ec1u d\u00f2ng l\u1ec7nh).
    \u2705 T\u1ef1 \u0111\u1ed9ng tr\u1ea3 v\u1ec1 gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c.<\/p>\n\n\n\n
    V\u00ed d\u1ee5:<\/p>\n\n\n\n
    add = lambda x, y: x + y\nprint(add(3, 5))  # K\u1ebft qu\u1ea3: 8\n<\/code><\/pre>\n\n\n\n
    \n\n\n\n
    \ud83d\udccc 2. So s\u00e1nh Lambda Function v\u1edbi H\u00e0m B\u00ecnh Th\u01b0\u1eddng<\/strong><\/h2>\n\n\n\n
    \u0110\u1ec3 hi\u1ec3u r\u00f5 h\u01a1n, h\u00e3y so s\u00e1nh c\u00e1ch vi\u1ebft m\u1ed9t h\u00e0m theo ki\u1ec3u truy\u1ec1n th\u1ed1ng v\u00e0 c\u00e1ch s\u1eed d\u1ee5ng lambda function.<\/p>\n\n\n\n
    \ud83d\udd39 H\u00e0m b\u00ecnh th\u01b0\u1eddng (def<\/code>)<\/strong><\/p>\n\n\n\n
    def square(x):\n    return x * x\n\nprint(square(5))  # K\u1ebft qu\u1ea3: 25\n<\/code><\/pre>\n\n\n\n
    \ud83d\udd39 Lambda function<\/strong><\/p>\n\n\n\n
    square = lambda x: x * x\nprint(square(5))  # K\u1ebft qu\u1ea3: 25\n<\/code><\/pre>\n\n\n\n
    \ud83d\udca1 Nh\u1eadn x\u00e9t:<\/strong><\/p>\n\n\n\n
      \n
    • C\u00e1ch d\u00f9ng lambda<\/code> gi\u00fap code ng\u1eafn h\u01a1n<\/strong>, lo\u1ea1i b\u1ecf vi\u1ec7c khai b\u00e1o def<\/code>, return<\/code>, v\u00e0 {}<\/code>.<\/li>\n\n\n\n
    • Lambda ph\u00f9 h\u1ee3p v\u1edbi c\u00e1c h\u00e0m \u0111\u01a1n gi\u1ea3n, s\u1eed d\u1ee5ng m\u1ed9t l\u1ea7n<\/strong>.<\/li>\n<\/ul>\n\n\n\n
      \n\n\n\n
      \ud83d\udccc 3. Khi n\u00e0o n\u00ean s\u1eed d\u1ee5ng Lambda Function?<\/strong><\/h2>\n\n\n\n
      \u2705 Khi c\u1ea7n vi\u1ebft h\u00e0m ng\u1eafn g\u1ecdn<\/strong> \u0111\u1ec3 x\u1eed l\u00fd nhanh m\u1ed9t t\u00e1c v\u1ee5 \u0111\u01a1n gi\u1ea3n.
      \u2705 Khi c\u1ea7n h\u00e0m \u1ea9n danh<\/strong>, kh\u00f4ng c\u1ea7n l\u01b0u l\u1ea1i trong b\u1ed9 nh\u1edb.
      \u2705 Khi s\u1eed d\u1ee5ng h\u00e0m nh\u01b0 m\u1ed9t \u0111\u1ed1i s\u1ed1<\/strong> trong c\u00e1c h\u00e0m b\u1eadc cao (map()<\/code>, filter()<\/code>, sorted()<\/code>, reduce()<\/code>).
      \u2705 Khi vi\u1ebft bi\u1ec3u th\u1ee9c to\u00e1n h\u1ecdc nhanh<\/strong>, kh\u00f4ng c\u1ea7n khai b\u00e1o h\u00e0m \u0111\u1ea7y \u0111\u1ee7.<\/p>\n\n\n\n
      \ud83d\udca1 Khi n\u00e0o kh\u00f4ng n\u00ean d\u00f9ng Lambda?<\/strong>
      \u274c Khi h\u00e0m c\u00f3 logic ph\u1ee9c t\u1ea1p, c\u1ea7n nhi\u1ec1u d\u00f2ng code.
      \u274c Khi c\u1ea7n debug d\u1ec5 d\u00e0ng h\u01a1n \u2013 Lambda function kh\u00f4ng c\u00f3 t\u00ean, n\u00ean l\u1ed7i s\u1ebd kh\u00f3 t\u00ecm h\u01a1n.
      \u274c Khi c\u1ea7n t\u00e1i s\u1eed d\u1ee5ng h\u00e0m nhi\u1ec1u l\u1ea7n.<\/p>\n\n\n\n
      \n\n\n\n
      \ud83d\udccc 4. \u1ee8ng d\u1ee5ng th\u1ef1c t\u1ebf c\u1ee7a Lambda Function<\/strong><\/h2>\n\n\n\n
      \ud83c\udfaf 4.1. D\u00f9ng Lambda v\u1edbi map()<\/code> \u0111\u1ec3 bi\u1ebfn \u0111\u1ed5i danh s\u00e1ch<\/strong><\/h3>\n\n\n\n
      H\u00e0m map()<\/code> gi\u00fap \u00e1p d\u1ee5ng m\u1ed9t h\u00e0m l\u00ean t\u1eebng ph\u1ea7n t\u1eed<\/strong> c\u1ee7a danh s\u00e1ch.<\/p>\n\n\n\n
      numbers = [1, 2, 3, 4, 5]\nsquared_numbers = list(map(lambda x: x**2, numbers))\nprint(squared_numbers)  # K\u1ebft qu\u1ea3: [1, 4, 9, 16, 25]\n<\/code><\/pre>\n\n\n\n
      \ud83d\udca1 L\u1ee3i \u00edch:<\/strong>
      \u2705 Kh\u00f4ng c\u1ea7n vi\u1ebft v\u00f2ng l\u1eb7p for<\/code>.
      \u2705 Gi\u00fap code ng\u1eafn g\u1ecdn v\u00e0 d\u1ec5 \u0111\u1ecdc h\u01a1n.<\/p>\n\n\n\n
      \n\n\n\n
      \ud83c\udfaf 4.2. D\u00f9ng Lambda v\u1edbi filter()<\/code> \u0111\u1ec3 l\u1ecdc danh s\u00e1ch<\/strong><\/h3>\n\n\n\n
      H\u00e0m filter()<\/code> gi\u00fap l\u1ecdc d\u1eef li\u1ec7u theo \u0111i\u1ec1u ki\u1ec7n<\/strong>.<\/p>\n\n\n\n
      V\u00ed d\u1ee5: L\u1ecdc c\u00e1c s\u1ed1 ch\u1eb5n trong danh s\u00e1ch:<\/p>\n\n\n\n
      numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]\neven_numbers = list(filter(lambda x: x % 2 == 0, numbers))\nprint(even_numbers)  # K\u1ebft qu\u1ea3: [2, 4, 6, 8, 10]\n<\/code><\/pre>\n\n\n\n
      \n\n\n\n
      \ud83c\udfaf 4.3. D\u00f9ng Lambda v\u1edbi sorted()<\/code> \u0111\u1ec3 s\u1eafp x\u1ebfp danh s\u00e1ch theo ti\u00eau ch\u00ed t\u00f9y ch\u1ec9nh<\/strong><\/h3>\n\n\n\n
      B\u1ea1n c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng lambda \u0111\u1ec3 s\u1eafp x\u1ebfp danh s\u00e1ch ph\u1ee9c t\u1ea1p h\u01a1n<\/strong>.<\/p>\n\n\n\n
      V\u00ed d\u1ee5: S\u1eafp x\u1ebfp danh s\u00e1ch sinh vi\u00ean theo tu\u1ed5i:<\/p>\n\n\n\n
      students = [\n    {\"name\": \"An\", \"age\": 20},\n    {\"name\": \"B\u1ea3o\", \"age\": 22},\n    {\"name\": \"Ch\u00e2u\", \"age\": 19}\n]\n\nsorted_students = sorted(students, key=lambda x: x[\"age\"])\nprint(sorted_students)\n<\/code><\/pre>\n\n\n\n
      \n\n\n\n
      \ud83c\udfaf 4.4. D\u00f9ng Lambda trong to\u00e1n h\u1ecdc \u2013 Vi\u1ebft bi\u1ec3u th\u1ee9c \u0111\u01a1n gi\u1ea3n nhanh ch\u00f3ng<\/strong><\/h3>\n\n\n\n
      Lambda r\u1ea5t h\u1eefu \u00edch khi x\u1eed l\u00fd to\u00e1n h\u1ecdc nhanh ch\u00f3ng.<\/p>\n\n\n\n
      V\u00ed d\u1ee5: Vi\u1ebft h\u00e0m t\u00ednh di\u1ec7n t\u00edch h\u00ecnh ch\u1eef nh\u1eadt:<\/p>\n\n\n\n
      area = lambda length, width: length * width\nprint(area(5, 3))  # K\u1ebft qu\u1ea3: 15\n<\/code><\/pre>\n\n\n\n
      \n\n\n\n
      \ud83c\udfaf 4.5. D\u00f9ng Lambda v\u1edbi reduce()<\/code> \u0111\u1ec3 t\u00ednh to\u00e1n t\u1ed5ng th\u1ec3<\/strong><\/h3>\n\n\n\n
      H\u00e0m reduce()<\/code> (thu\u1ed9c module functools<\/code>) gi\u00fap t\u00ednh to\u00e1n t\u00edch l\u0169y<\/strong> tr\u00ean danh s\u00e1ch.<\/p>\n\n\n\n
      V\u00ed d\u1ee5: T\u00ednh t\u00edch c\u1ee7a m\u1ed9t danh s\u00e1ch s\u1ed1:<\/p>\n\n\n\n
      from functools import reduce\n\nnumbers = [1, 2, 3, 4, 5]\nproduct = reduce(lambda x, y: x * y, numbers)\nprint(product)  # K\u1ebft qu\u1ea3: 120\n<\/code><\/pre>\n\n\n\n
      \n\n\n\n
      \ud83d\udccc 5. \u01afu \u0111i\u1ec3m v\u00e0 Nh\u01b0\u1ee3c \u0111i\u1ec3m c\u1ee7a Lambda Function<\/strong><\/h2>\n\n\n\n
      \ud83d\udd39 \u01afu \u0111i\u1ec3m:<\/strong>
      \u2705 Gi\u00fap vi\u1ebft code ng\u1eafn g\u1ecdn, d\u1ec5 hi\u1ec3u.
      \u2705 Tr\u1ef1c quan, kh\u00f4ng c\u1ea7n \u0111\u1ecbnh ngh\u0129a h\u00e0m ri\u00eang bi\u1ec7t.
      \u2705 K\u1ebft h\u1ee3p t\u1ed1t v\u1edbi c\u00e1c h\u00e0m b\u1eadc cao nh\u01b0 map()<\/code>, filter()<\/code>, reduce()<\/code>.
      \u2705 T\u1ed1i \u01b0u h\u00f3a hi\u1ec7u su\u1ea5t khi ch\u1ec9 c\u1ea7n d\u00f9ng h\u00e0m m\u1ed9t l\u1ea7n.<\/p>\n\n\n\n
      \ud83d\udd39 Nh\u01b0\u1ee3c \u0111i\u1ec3m:<\/strong>
      \u274c Kh\u00f3 \u0111\u1ecdc h\u01a1n n\u1ebfu qu\u00e1 l\u1ea1m d\u1ee5ng.
      \u274c Kh\u00f4ng th\u1ec3 ch\u1ee9a nhi\u1ec1u d\u00f2ng l\u1ec7nh.
      \u274c Kh\u00f4ng th\u1ec3 debug d\u1ec5 d\u00e0ng do kh\u00f4ng c\u00f3 t\u00ean h\u00e0m.<\/p>\n\n\n\n
      \n\n\n\n
      \ud83d\udccc 6. T\u1ed5ng k\u1ebft<\/strong><\/h2>\n\n\n\n
      Lambda Function l\u00e0 m\u1ed9t c\u00f4ng c\u1ee5 c\u1ef1c k\u1ef3 h\u1eefu \u00edch gi\u00fap vi\u1ebft code Python ng\u1eafn g\u1ecdn, hi\u1ec7u qu\u1ea3<\/strong> h\u01a1n. N\u00f3 ph\u00f9 h\u1ee3p khi l\u00e0m vi\u1ec7c v\u1edbi danh s\u00e1ch, to\u00e1n h\u1ecdc v\u00e0 c\u00e1c thao t\u00e1c d\u1eef li\u1ec7u nhanh ch\u00f3ng<\/strong>. Tuy nhi\u00ean, b\u1ea1n c\u0169ng c\u1ea7n s\u1eed d\u1ee5ng h\u1ee3p l\u00fd<\/strong>, tr\u00e1nh l\u00e0m code kh\u00f3 \u0111\u1ecdc v\u00e0 kh\u00f3 b\u1ea3o tr\u00ec.<\/p>\n\n\n\n
      \ud83d\udccc B\u1ea1n \u0111\u00e3 th\u1eed s\u1eed d\u1ee5ng lambda function ch\u01b0a? H\u00e3y \u00e1p d\u1ee5ng ngay h\u00f4m nay v\u00e0 chia s\u1ebb tr\u1ea3i nghi\u1ec7m c\u1ee7a b\u1ea1n!<\/strong> \u2b07\ufe0f\ud83d\udcac<\/p>\n\n\n\n
      #Python #LambdaFunction #LapTrinhPython #PythonTips #CodeOptimization \ud83d\ude80<\/p>\n","protected":false},"excerpt":{"rendered":"
      Lambda function l\u00e0 m\u1ed9t trong nh\u1eefng t\u00ednh n\u0103ng \u0111\u1ed9c \u0111\u00e1o v\u00e0 m\u1ea1nh m\u1ebd c\u1ee7a Python, cho ph\u00e9p b\u1ea1n t\u1ea1o nhanh m\u1ed9t h\u00e0m ch\u1ec9 trong m\u1ed9t d\u00f2ng code. \u0110\u00e2y l\u00e0 c\u00f4ng c\u1ee5 c\u1ef1c…<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-428","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/news.techjunior.vn\/index.php?rest_route=\/wp\/v2\/posts\/428","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/news.techjunior.vn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/news.techjunior.vn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/news.techjunior.vn\/index.php?rest_route=\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/news.techjunior.vn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=428"}],"version-history":[{"count":1,"href":"https:\/\/news.techjunior.vn\/index.php?rest_route=\/wp\/v2\/posts\/428\/revisions"}],"predecessor-version":[{"id":430,"href":"https:\/\/news.techjunior.vn\/index.php?rest_route=\/wp\/v2\/posts\/428\/revisions\/430"}],"wp:attachment":[{"href":"https:\/\/news.techjunior.vn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=428"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/news.techjunior.vn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=428"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/news.techjunior.vn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=428"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}