{"id":929172,"date":"2024-12-26T16:50:17","date_gmt":"2024-12-26T08:50:17","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/929172.html"},"modified":"2024-12-26T16:50:19","modified_gmt":"2024-12-26T08:50:19","slug":"python-%e5%a6%82%e4%bd%95%e7%94%a8for","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/929172.html","title":{"rendered":"python \u5982\u4f55\u7528for"},"content":{"rendered":"

\"python<\/p>\n

Python\u4e2d\u7684for\u5faa\u73af\u53ef\u4ee5\u7528\u4e8e\u904d\u5386\u4efb\u4f55\u53ef\u8fed\u4ee3\u5bf9\u8c61\uff0c\u4f8b\u5982\u5217\u8868\u3001\u5b57\u7b26\u4e32\u3001\u5b57\u5178\u3001\u96c6\u5408\u7b49\u3002\u5e38\u89c1\u7684\u7528\u6cd5\u5305\u62ec\uff1a\u904d\u5386\u5217\u8868\u3001\u904d\u5386\u5b57\u7b26\u4e32\u3001\u4f7f\u7528range\u51fd\u6570\u751f\u6210\u6570\u5b57\u5e8f\u5217\u3001\u5d4c\u5957\u5faa\u73af\u3002<\/strong> \u4e0b\u9762\u5c06\u8be6\u7ec6\u4ecb\u7ecd\u5982\u4f55\u5728Python\u4e2d\u4f7f\u7528for\u5faa\u73af\uff0c\u5e76\u63d0\u4f9b\u4e00\u4e9b\u5b9e\u7528\u7684\u4f8b\u5b50\u548c\u6280\u5de7\u3002<\/p>\n<\/p>\n

\u4e00\u3001\u904d\u5386\u5217\u8868<\/p>\n<\/p>\n

\u5728Python\u4e2d\uff0c\u5217\u8868\u662f\u6700\u5e38\u7528\u7684\u6570\u636e\u7ed3\u6784\u4e4b\u4e00\uff0cfor\u5faa\u73af\u53ef\u4ee5\u8f7b\u677e\u5730\u904d\u5386\u5217\u8868\u4e2d\u7684\u5143\u7d20\u3002<\/p>\n<\/p>\n

fruits = ['apple', 'banana', 'cherry']<\/p>\n
for fruit in fruits:<\/p>\n
    print(fruit)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0cfor\u5faa\u73af\u4f9d\u6b21\u5c06\u5217\u8868\u4e2d\u7684\u6bcf\u4e2a\u5143\u7d20\u8d4b\u503c\u7ed9\u53d8\u91cffruit<\/code>\uff0c\u7136\u540e\u5728\u5faa\u73af\u4f53\u4e2d\u6253\u5370\u51fa\u6765\u3002<\/p>\n<\/p>\n
\u4e8c\u3001\u904d\u5386\u5b57\u7b26\u4e32<\/p>\n<\/p>\n
\u5b57\u7b26\u4e32\u5728Python\u4e2d\u662f\u53ef\u8fed\u4ee3\u5bf9\u8c61\uff0c\u56e0\u6b64\u4e5f\u53ef\u4ee5\u4f7f\u7528for\u5faa\u73af\u6765\u904d\u5386\u5b57\u7b26\u4e32\u4e2d\u7684\u6bcf\u4e00\u4e2a\u5b57\u7b26\u3002<\/p>\n<\/p>\n
text = "hello"<\/p>\n
for char in text:<\/p>\n
    print(char)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u91cc\uff0cfor\u5faa\u73af\u9010\u4e2a\u904d\u5386\u5b57\u7b26\u4e32text<\/code>\u4e2d\u7684\u5b57\u7b26\uff0c\u5e76\u6253\u5370\u51fa\u6765\u3002<\/p>\n<\/p>\n
\u4e09\u3001\u4f7f\u7528range\u51fd\u6570\u751f\u6210\u6570\u5b57\u5e8f\u5217<\/p>\n<\/p>\n
range()<\/code>\u51fd\u6570\u662fPython\u4e2d\u4e00\u4e2a\u975e\u5e38\u6709\u7528\u7684\u5de5\u5177\uff0c\u7528\u4e8e\u751f\u6210\u4e00\u4e2a\u6570\u5b57\u5e8f\u5217\uff0c\u5e38\u7528\u4e8e\u9700\u8981\u6267\u884c\u56fa\u5b9a\u6b21\u6570\u7684\u5faa\u73af\u4e2d\u3002<\/p>\n<\/p>\n
for i in range(5):<\/p>\n
    print(i)<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u8fd9\u6bb5\u4ee3\u7801\u4f1a\u6253\u5370\u4ece0\u52304\u7684\u6570\u5b57\u3002range(5)<\/code>\u751f\u6210\u4e00\u4e2a\u4ece0\u52304\u7684\u5e8f\u5217\u3002<\/p>\n<\/p>\n
range()\u51fd\u6570\u7684\u51e0\u4e2a\u7528\u6cd5\uff1a<\/strong><\/p>\n<\/p>\n
    \n
  • range(stop)<\/code>\uff1a\u751f\u6210\u4ece0\u5230stop-1\u7684\u6570\u5b57\u3002<\/li>\n
  • range(start, stop)<\/code>\uff1a\u751f\u6210\u4ecestart\u5230stop-1\u7684\u6570\u5b57\u3002<\/li>\n
  • range(start, stop, step)<\/code>\uff1a\u751f\u6210\u4ecestart\u5230stop-1\u7684\u6570\u5b57\uff0c\u6b65\u957f\u4e3astep\u3002<\/li>\n<\/ul>\n
    for i in range(2, 10, 2):<\/p>\n
        print(i)<\/p>\n
    <\/code><\/pre>\n<\/p>\n
    \u8fd9\u4e2a\u4f8b\u5b50\u4f1a\u6253\u53702, 4, 6, 8\uff0c\u56e0\u4e3a\u6b65\u957f\u8bbe\u7f6e\u4e3a2\u3002<\/p>\n<\/p>\n
    \u56db\u3001\u904d\u5386\u5b57\u5178<\/p>\n<\/p>\n
    \u5b57\u5178\u662fPython\u4e2d\u53e6\u4e00\u79cd\u5e38\u89c1\u7684\u6570\u636e\u7ed3\u6784\uff0cfor\u5faa\u73af\u53ef\u4ee5\u7528\u4e8e\u904d\u5386\u5b57\u5178\u7684\u952e\u3001\u503c\u6216\u952e\u503c\u5bf9\u3002<\/p>\n<\/p>\n
    person = {'name': 'Alice', 'age': 25, 'city': 'New York'}<\/p>\n
    for key in person:<\/p>\n
        print(key, person[key])<\/p>\n
    <\/code><\/pre>\n<\/p>\n
    \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0cfor\u5faa\u73af\u904d\u5386\u5b57\u5178person<\/code>\u7684\u952e\uff0c\u5e76\u901a\u8fc7\u952e\u8bbf\u95ee\u5bf9\u5e94\u7684\u503c\u3002<\/p>\n<\/p>\n
    \u4e94\u3001\u4f7f\u7528enumerate\u51fd\u6570\u83b7\u53d6\u7d22\u5f15<\/p>\n<\/p>\n
    \u5f53\u9700\u8981\u5728\u5faa\u73af\u4e2d\u540c\u65f6\u83b7\u53d6\u5143\u7d20\u53ca\u5176\u7d22\u5f15\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528enumerate()<\/code>\u51fd\u6570\u3002<\/p>\n<\/p>\n
    colors = ['red', 'green', 'blue']<\/p>\n
    for index, color in enumerate(colors):<\/p>\n
        print(index, color)<\/p>\n
    <\/code><\/pre>\n<\/p>\n
    enumerate()<\/code>\u51fd\u6570\u8fd4\u56de\u4e00\u4e2a\u5305\u542b\u7d22\u5f15\u548c\u503c\u7684\u5143\u7ec4\uff0cindex<\/code>\u548ccolor<\/code>\u5206\u522b\u4ee3\u8868\u7d22\u5f15\u548c\u989c\u8272\u503c\u3002<\/p>\n<\/p>\n
    \u516d\u3001\u5d4c\u5957\u5faa\u73af<\/p>\n<\/p>\n
    \u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0c\u53ef\u80fd\u9700\u8981\u4f7f\u7528\u5d4c\u5957\u5faa\u73af\uff0c\u4f8b\u5982\u904d\u5386\u4e00\u4e2a\u4e8c\u7ef4\u5217\u8868\u3002<\/p>\n<\/p>\n
    matrix = [<\/p>\n
        [1, 2, 3],<\/p>\n
        [4, 5, 6],<\/p>\n
        [7, 8, 9]<\/p>\n
    ]<\/p>\n
    for row in matrix:<\/p>\n
        for num in row:<\/p>\n
            print(num, end=' ')<\/p>\n
        print()<\/p>\n
    <\/code><\/pre>\n<\/p>\n
    \u8fd9\u4e2a\u4f8b\u5b50\u904d\u5386\u4e86\u4e00\u4e2a\u4e8c\u7ef4\u5217\u8868matrix<\/code>\uff0c\u5e76\u6253\u5370\u6bcf\u4e2a\u5143\u7d20\u3002<\/p>\n<\/p>\n
    \u4e03\u3001\u5faa\u73af\u63a7\u5236\uff1abreak\u548ccontinue<\/p>\n<\/p>\n
    \u5728for\u5faa\u73af\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528break<\/code>\u548ccontinue<\/code>\u6765\u63a7\u5236\u5faa\u73af\u7684\u6267\u884c\u3002<\/p>\n<\/p>\n
      \n
    1. break<\/strong>\uff1a\u7528\u4e8e\u7ec8\u6b62\u5faa\u73af\u3002<\/li>\n<\/ol>\n
      for num in range(10):<\/p>\n
          if num == 5:<\/p>\n
              break<\/p>\n
          print(num)<\/p>\n
      <\/code><\/pre>\n<\/p>\n
      \u8fd9\u6bb5\u4ee3\u7801\u5728\u6570\u5b575\u65f6\u7ec8\u6b62\u5faa\u73af\u3002<\/p>\n<\/p>\n
        \n
      1. continue<\/strong>\uff1a\u7528\u4e8e\u8df3\u8fc7\u5f53\u524d\u8fed\u4ee3\u7684\u5269\u4f59\u90e8\u5206\uff0c\u76f4\u63a5\u8fdb\u5165\u4e0b\u4e00\u6b21\u8fed\u4ee3\u3002<\/li>\n<\/ol>\n
        for num in range(10):<\/p>\n
            if num % 2 == 0:<\/p>\n
                continue<\/p>\n
            print(num)<\/p>\n
        <\/code><\/pre>\n<\/p>\n
        \u8fd9\u4e2a\u4f8b\u5b50\u4ec5\u6253\u5370\u5947\u6570\u3002<\/p>\n<\/p>\n
        \u516b\u3001\u4f7f\u7528else\u5b50\u53e5<\/p>\n<\/p>\n
        \u5728for\u5faa\u73af\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528else<\/code>\u5b50\u53e5\u3002\u5f53\u5faa\u73af\u6b63\u5e38\u7ed3\u675f\u65f6\uff0celse<\/code>\u5b50\u53e5\u4e2d\u7684\u4ee3\u7801\u4f1a\u6267\u884c\u3002\u5982\u679c\u5faa\u73af\u88abbreak<\/code>\u7ec8\u6b62\uff0c\u5219\u4e0d\u4f1a\u6267\u884c\u3002<\/p>\n<\/p>\n
        for num in range(10):<\/p>\n
            if num == 5:<\/p>\n
                break<\/p>\n
        else:<\/p>\n
            print("Loop finished without break")<\/p>\n
        <\/code><\/pre>\n<\/p>\n
        \u7531\u4e8e\u5faa\u73af\u5728\u6570\u5b575\u65f6\u88ab\u4e2d\u65ad\uff0celse<\/code>\u4e2d\u7684\u4ee3\u7801\u4e0d\u4f1a\u6267\u884c\u3002<\/p>\n<\/p>\n
        \u4e5d\u3001for\u5faa\u73af\u7684\u6027\u80fd\u4f18\u5316<\/p>\n<\/p>\n
        \u5728\u5904\u7406\u5927\u578b\u6570\u636e\u96c6\u6216\u590d\u6742\u8fd0\u7b97\u65f6\uff0cfor\u5faa\u73af\u53ef\u80fd\u4f1a\u6210\u4e3a\u6027\u80fd\u74f6\u9888\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u4f18\u5316for\u5faa\u73af\u6027\u80fd\u7684\u5efa\u8bae\uff1a<\/p>\n<\/p>\n
          \n
        1. \n
          \u51cf\u5c11\u5faa\u73af\u5185\u90e8\u7684\u8ba1\u7b97<\/strong>\uff1a\u5c06\u4e0d\u53d8\u7684\u8ba1\u7b97\u79fb\u51fa\u5faa\u73af\u3002<\/p>\n<\/p>\n<\/li>\n
        2. \n
          \u4f7f\u7528\u751f\u6210\u5668<\/strong>\uff1a\u5f53\u5904\u7406\u5927\u91cf\u6570\u636e\u65f6\uff0c\u4f7f\u7528\u751f\u6210\u5668\u53ef\u4ee5\u8282\u7701\u5185\u5b58\u3002<\/p>\n<\/p>\n<\/li>\n
        3. \n
          \u907f\u514d\u4e0d\u5fc5\u8981\u7684\u51fd\u6570\u8c03\u7528<\/strong>\uff1a\u5728\u5faa\u73af\u4e2d\u9891\u7e41\u8c03\u7528\u51fd\u6570\u53ef\u80fd\u4f1a\u964d\u4f4e\u6027\u80fd\u3002<\/p>\n<\/p>\n<\/li>\n
        4. \n
          \u4f7f\u7528\u5217\u8868\u63a8\u5bfc\u5f0f<\/strong>\uff1a\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0c\u5217\u8868\u63a8\u5bfc\u5f0f\u6bd4for\u5faa\u73af\u66f4\u9ad8\u6548\u3002<\/p>\n<\/p>\n<\/li>\n<\/ol>\n
          squares = [x2 for x in range(10)]<\/p>\n
          <\/code><\/pre>\n<\/p>\n
          \u603b\u7ed3\uff1a<\/p>\n<\/p>\n
          Python\u7684for\u5faa\u73af\u529f\u80fd\u5f3a\u5927\u4e14\u7075\u6d3b\uff0c\u80fd\u591f\u8f7b\u677e\u904d\u5386\u5404\u79cd\u53ef\u8fed\u4ee3\u5bf9\u8c61\u3002\u901a\u8fc7\u7ed3\u5408range()<\/code>\u3001enumerate()<\/code>\u3001\u5d4c\u5957\u5faa\u73af\u3001\u63a7\u5236\u8bed\u53e5\uff08break<\/code>\u3001continue<\/code>\uff09\u548celse<\/code>\u5b50\u53e5\uff0c\u53ef\u4ee5\u5b9e\u73b0\u590d\u6742\u7684\u5faa\u73af\u903b\u8f91\u3002\u540c\u65f6\uff0c\u901a\u8fc7\u5e94\u7528\u6027\u80fd\u4f18\u5316\u6280\u5de7\uff0c\u53ef\u4ee5\u5728\u5904\u7406\u5927\u89c4\u6a21\u6570\u636e\u65f6\u63d0\u9ad8\u5faa\u73af\u7684\u6548\u7387\u3002\u638c\u63e1\u8fd9\u4e9b\u6280\u5de7\u5c06\u5e2e\u52a9\u4f60\u5728Python\u7f16\u7a0b\u4e2d\u66f4\u9ad8\u6548\u5730\u89e3\u51b3\u95ee\u9898\u3002<\/p>\n<\/p>\n
          \u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
           \u5982\u4f55\u5728Python\u4e2d\u4f7f\u7528for\u5faa\u73af\u904d\u5386\u5217\u8868\uff1f<\/strong>
          \u5728Python\u4e2d\uff0cfor\u5faa\u73af\u53ef\u4ee5\u8f7b\u677e\u904d\u5386\u5217\u8868\u4e2d\u7684\u6bcf\u4e2a\u5143\u7d20\u3002\u4f7f\u7528for item in list:<\/code>\u7684\u8bed\u6cd5\uff0c\u53ef\u4ee5\u4f9d\u6b21\u8bbf\u95ee\u5217\u8868\u7684\u6240\u6709\u5143\u7d20\u3002\u4f8b\u5982\uff1a<\/p>\n
          my_list = [1, 2, 3, 4, 5]\nfor item in my_list:\n    print(item)\n<\/code><\/pre>\n
          \u4e0a\u8ff0\u4ee3\u7801\u5c06\u4f9d\u6b21\u6253\u5370\u51fa\u5217\u8868\u4e2d\u7684\u6bcf\u4e2a\u6570\u5b57\u3002\u4f7f\u7528for\u5faa\u73af\uff0c\u4f60\u53ef\u4ee5\u5bf9\u6bcf\u4e2a\u5143\u7d20\u8fdb\u884c\u64cd\u4f5c\uff0c\u6bd4\u5982\u8ba1\u7b97\u3001\u4fee\u6539\u6216\u7b5b\u9009\u3002<\/p>\n
          \u5982\u4f55\u5728Python\u4e2d\u4f7f\u7528for\u5faa\u73af\u904d\u5386\u5b57\u5178\u7684\u952e\u548c\u503c\uff1f<\/strong>
          \u5728Python\u4e2d\uff0cfor\u5faa\u73af\u53ef\u4ee5\u7528\u4e8e\u904d\u5386\u5b57\u5178\u7684\u952e\u6216\u503c\u3002\u8981\u904d\u5386\u5b57\u5178\u7684\u952e\uff0c\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528for key in dict:<\/code>\u7684\u5f62\u5f0f\u3002\u5982\u679c\u60f3\u540c\u65f6\u83b7\u53d6\u952e\u548c\u503c\uff0c\u53ef\u4ee5\u4f7f\u7528dict.items()<\/code>\u65b9\u6cd5\u3002\u4f8b\u5982\uff1a<\/p>\n
          my_dict = {'a': 1, 'b': 2, 'c': 3}\nfor key, value in my_dict.items():\n    print(f"Key: {key}, Value: {value}")\n<\/code><\/pre>\n
          \u8fd9\u6bb5\u4ee3\u7801\u5c06\u8f93\u51fa\u5b57\u5178\u4e2d\u7684\u6bcf\u4e2a\u952e\u53ca\u5176\u5bf9\u5e94\u7684\u503c\uff0c\u65b9\u4fbf\u8fdb\u884c\u590d\u6742\u7684\u6570\u636e\u5904\u7406\u6216\u5206\u6790\u3002<\/p>\n
          \u5982\u4f55\u5728Python\u4e2d\u4f7f\u7528for\u5faa\u73af\u4e0erange\u51fd\u6570\u7ed3\u5408\uff1f<\/strong>
          \u5728\u9700\u8981\u751f\u6210\u4e00\u7cfb\u5217\u6570\u5b57\u65f6\uff0cfor\u5faa\u73af\u4e0erange()<\/code>\u51fd\u6570\u7ed3\u5408\u4f7f\u7528\u975e\u5e38\u6709\u6548\u3002range()<\/code>\u51fd\u6570\u53ef\u4ee5\u751f\u6210\u6307\u5b9a\u8303\u56f4\u7684\u6574\u6570\u5e8f\u5217\uff0c\u5e38\u7528\u4e8e\u9700\u8981\u5faa\u73af\u7279\u5b9a\u6b21\u6570\u7684\u573a\u666f\u3002\u4f8b\u5982\uff1a<\/p>\n
          for i in range(5):\n    print(i)\n<\/code><\/pre>\n
          \u6b64\u4ee3\u7801\u5c06\u6253\u5370\u51fa0\u52304\u7684\u6570\u5b57\u3002\u5982\u679c\u9700\u8981\u4ece1\u5f00\u59cb\uff0c\u53ef\u4ee5\u4f7f\u7528range(1, 6)<\/code>\uff0c\u8fd9\u5c06\u8f93\u51fa1\u52305\u7684\u6570\u5b57\u3002\u901a\u8fc7\u8c03\u6574range()<\/code>\u7684\u53c2\u6570\uff0c\u8fd8\u53ef\u4ee5\u63a7\u5236\u6b65\u957f\uff0c\u5b9e\u73b0\u66f4\u590d\u6742\u7684\u5faa\u73af\u9700\u6c42\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"Python\u4e2d\u7684for\u5faa\u73af\u53ef\u4ee5\u7528\u4e8e\u904d\u5386\u4efb\u4f55\u53ef\u8fed\u4ee3\u5bf9\u8c61\uff0c\u4f8b\u5982\u5217\u8868\u3001\u5b57\u7b26\u4e32\u3001\u5b57\u5178\u3001\u96c6\u5408\u7b49\u3002\u5e38\u89c1\u7684\u7528\u6cd5\u5305\u62ec\uff1a\u904d\u5386\u5217\u8868 […]","protected":false},"author":3,"featured_media":929178,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[37],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/929172"}],"collection":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/comments?post=929172"}],"version-history":[{"count":"1","href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/929172\/revisions"}],"predecessor-version":[{"id":929180,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/929172\/revisions\/929180"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/929178"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=929172"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=929172"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=929172"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}