1. for - else<\/strong><\/span><\/div>\n
\u4ec0\u4e48\uff1f\u4e0d\u662f if \u548c else \u624d\u662f\u539f\u914d\u5417\uff1fNo\uff0c\u4f60\u53ef\u80fd\u4e0d\u77e5\u9053\uff0celse \u662f\u4e2a\u811a\u8e29\u4e24\u53ea\u8239\u7684\u5bb6\u4f19\uff0cfor \u548c else \u4e5f\u662f\u4e00\u5bf9\uff0c\u800c\u4e14\u662f\u5408\u6cd5\u7684\u3002\u5341\u5927\u88c5B\u8bed\u6cd5\uff0cfor-else \u7edd\u5bf9\u7b97\u5f97\u4e0a\u5357\u65e0\u6e7e\uff01\u4e0d\u4fe1\uff0c\u8bf7\u770b\uff1a<\/p>\n
>> for i in [1,2,3,4]:\r\nprint(i)\r\nelse:\r\nprint(i, '\u6211\u662felse')\r\n\r\n1\r\n2\r\n3\r\n4 \u6211\u662felse\r\n<\/pre>\n
\u5982\u679c\u5728 for \u548c else \u4e4b\u95f4\uff08\u5faa\u73af\u4f53\u5185\uff09\u6709\u7b2c\u4e09\u8005 if \u63d2\u8db3\uff0c\u4e5f\u4e0d\u4f1a\u5f71\u54cd for \u548c else \u7684\u5173\u7cfb\u3002\u56e0\u4e3a for \u7684\u7ea7\u522b\u6bd4 if \u9ad8\uff0celse \u53c8\u662f\u4e00\u4e2a\u6500\u9644\u6743\u8d35\u7684\u5bb6\u4f19\uff0c\u6839\u672c\u4e0d\u5728\u4e4e\u662f\u5426\u6709 if\uff0c\u4ee5\u53ca\u662f\u5426\u6267\u884c\u4e86\u6ee1\u8db3 if \u6761\u4ef6\u7684\u8bed\u53e5\u3002else \u7684\u773c\u91cc\u53ea\u6709 for\uff0c\u53ea\u8981 for \u987a\u5229\u6267\u884c\u5b8c\u6bd5\uff0celse \u5c31\u4f1a\u5c41\u98a0\u513f\u5c41\u98a0\u513f\u5730\u8dd1\u4e00\u904d\uff1a<\/p>\n
>>> for i in [1,2,3,4]:\r\nif i > 2:\r\nprint(i)\r\nelse:\r\nprint(i, '\u6211\u662felse')\r\n4 \u6211\u662felse<\/pre>\n
\u90a3\u4e48\uff0c\u5982\u4f55\u62c6\u6563 for \u548c else \u8fd9\u5bf9\u51a4\u5bb6\u5462\uff1f\u53ea\u6709\u5f53 for \u5faa\u73af\u88ab break \u8bed\u53e5\u4e2d\u65ad\u4e4b\u540e\uff0c\u624d\u4f1a\u8df3\u8fc7 else \u8bed\u53e5\uff1a<\/p>\n
>>> for i in [1,2,3,4]:\r\nif i>2:\r\nprint(i)\r\nbreak\r\nelse:\r\nprint(i, '\u6211\u662felse')\r\n3<\/pre>\n
2. \u4e00\u9897\u661f(*)\u548c\u4e24\u9897\u661f(**)<\/strong><\/span><\/div>\n
\u6709\u6ca1\u6709\u53d1\u73b0\uff0c\u661f(*)\u771f\u662f\u4e00\u4e2a\u795e\u5947\u7684\u7b26\u53f7\uff01\u60f3\u4e00\u60f3\uff0c\u6ca1\u6709\u5b83\uff0cC\u8bed\u8a00\u8fd8\u6709\u5565\u597d\u73a9\u7684\uff1f\u540c\u6837\uff0c\u56e0\u4e3a\u6709\u5b83\uff0cPython \u624d\u4f1a\u5982\u6b64\u7684\u4eea\u6001\u4e07\u65b9\u3001\u98ce\u59ff\u7ef0\u7ea6\u3001\u695a\u695a\u52a8\u4eba\uff01Python \u51fd\u6570\u652f\u6301\u9ed8\u8ba4\u53c2\u6570\u548c\u53ef\u53d8\u53c2\u6570\uff0c\u4e00\u9897\u661f\u8868\u793a\u4e0d\u9650\u6570\u91cf\u7684\u5355\u503c\u53c2\u6570\uff0c\u4e24\u9897\u661f\u8868\u793a\u4e0d\u9650\u6570\u91cf\u7684\u952e\u503c\u5bf9\u53c2\u6570\u3002<\/p>\n
\u6211\u4eec\u8fd8\u662f\u4e3e\u4f8b\u8bf4\u660e\u5427\uff1a\u8bbe\u8ba1\u4e00\u4e2a\u51fd\u6570\uff0c\u8fd4\u56de\u591a\u4e2a\u8f93\u5165\u6570\u503c\u7684\u548c\u3002\u6211\u4eec\u56fa\u7136\u53ef\u4ee5\u628a\u8fd9\u4e9b\u8f93\u5165\u6570\u503c\u505a\u6210\u4e00\u4e2alist\u4f20\u7ed9\u51fd\u6570\uff0c\u4f46\u8fd9\u4e2a\u65b9\u6cd5\uff0c\u8fdc\u6ca1\u6709\u4f7f\u7528\u4e00\u9897\u661f\u7684\u53ef\u53d8\u53c2\u6570\u6765\u5f97\u4f18\u96c5\uff1a<\/p>\n
>>> def multi_sum(*args):\r\ns = 0\r\nfor item in args:\r\ns += item\r\nreturn s\r\n\r\n>>> multi_sum(3,4,5)\r\n12\r\n<\/pre>\n
Python \u51fd\u6570\u5141\u8bb8\u540c\u65f6\u5168\u90e8\u6216\u90e8\u5206\u4f7f\u7528\u56fa\u5b9a\u53c2\u6570\u3001\u9ed8\u8ba4\u53c2\u6570\u3001\u5355\u503c\uff08\u4e00\u9897\u661f\uff09\u53ef\u53d8\u53c2\u6570\u3001\u952e\u503c\u5bf9\uff08\u4e24\u9897\u661f\uff09\u53ef\u53d8\u53c2\u6570\uff0c\u4f7f\u7528\u65f6\u5fc5\u987b\u6309\u7167\u524d\u8ff0\u987a\u5e8f\u4e66\u5199\u3002<\/p>\n
>>> def do_something(name, age, gender='\u7537', *args, **kwds):\r\nprint('\u59d3\u540d\uff1a%s\uff0c\u5e74\u9f84\uff1a%d\uff0c\u6027\u522b\uff1a%s'%(name, age, gender))\r\nprint(args)\r\nprint(kwds)\r\n\r\n>>> do_something('xufive', 50, '\u7537', 175, 75, math=99, english=90)\r\n\u59d3\u540d\uff1axufive\uff0c\u5e74\u9f84\uff1a50\uff0c\u6027\u522b\uff1a\u7537\r\n(175, 75)\r\n{'math': 99, 'english': 90}<\/pre>\n
\u6b64\u5916\uff0c\u4e00\u9897\u661f\u548c\u4e24\u9897\u661f\u8fd8\u53ef\u7528\u4e8e\u5217\u8868\u3001\u5143\u7ec4\u3001\u5b57\u5178\u7684\u89e3\u5305\uff0c\u770b\u8d77\u6765\u66f4\u50cfC\u8bed\u8a00\uff1a<\/p>\n
>>> a = (1,2,3)\r\n>>> print(a)\r\n(1, 2, 3)\r\n>>> print(*a)\r\n1 2 3\r\n>>> b = [1,2,3]\r\n>>> print(b)\r\n[1, 2, 3]\r\n>>> print(*b)\r\n1 2 3\r\n>>> c = {'name':'xufive', 'age':51}\r\n>>> print(c)\r\n{'name': 'xufive', 'age': 51}\r\n>>> print(*c)\r\nname age\r\n>>> print('name:{name}, age:{age}'.format(**c))\r\nname:xufive, age:51<\/pre>\n
3. \u4e09\u5143\u8868\u8fbe\u5f0f<\/strong><\/span><\/div>\n
\u719f\u6089 C\/C++ \u7684\u7a0b\u5e8f\u5458\uff0c\u521d\u4e0a\u624b python \u65f6\uff0c\u4e00\u5b9a\u4f1a\u6000\u5ff5\u7ecf\u5178\u7684\u4e09\u5143\u64cd\u4f5c\u7b26\uff0c\u56e0\u4e3a\u60f3\u8868\u8fbe\u540c\u6837\u7684\u601d\u60f3\uff0c\u7528python \u5199\u8d77\u6765\u4f3c\u4e4e\u66f4\u9ebb\u70e6\u3002\u6bd4\u5982\uff1a<\/p>\n
>>> y = 5\r\n>>> if y < 0:\r\nprint('y\u662f\u4e00\u4e2a\u8d1f\u6570')\r\nelse:\r\nprint('y\u662f\u4e00\u4e2a\u975e\u8d1f\u6570')\r\n\r\ny\u662f\u4e00\u4e2a\u975e\u8d1f\u6570<\/pre>\n
\u5176\u5b9e\uff0cpython \u662f\u652f\u6301\u4e09\u5143\u8868\u8fbe\u5f0f\u7684\uff0c\u53ea\u662f\u7a0d\u5fae\u602a\u5f02\u4e86\u4e00\u70b9\uff0c\u7c7b\u4f3c\u4e8e\u6211\u4eec\u5c71\u4e1c\u4eba\u8bb2\u8bdd\u3002\u6bd4\u5982\uff0c\u5c71\u4e1c\u4eba\u6700\u559c\u6b22\u7528\u5012\u88c5\u53e5\uff1a\u6253\u7403\u53bb\u5427\uff0c\u8981\u662f\u4e0d\u4e0b\u96e8\u7684\u8bdd\uff1b\u4e0b\u96e8\uff0c\u54b1\u5c31\u53bb\u81ea\u4e60\u5ba4\u3002\u7ffb\u8bd1\u6210\u4e09\u5143\u8868\u8fbe\u5f0f\u5c31\u662f\uff1a<\/p>\n
\u6253\u7403\u53bb\u5427 if \u4e0d\u4e0b\u96e8 else \u53bb\u81ea\u4e60\u5ba4<\/p>\n
\u6765\u770b\u770b\u4e09\u5143\u8868\u8fbe\u5f0f\u5177\u4f53\u7684\u4f7f\u7528\uff1a<\/p>\n
>>> y = 5\r\n>>> print('y\u662f\u4e00\u4e2a\u8d1f\u6570' if y < 0 else 'y\u662f\u4e00\u4e2a\u975e\u8d1f\u6570')\r\ny\u662f\u4e00\u4e2a\u975e\u8d1f\u6570\r\n\r\npython \u7684\u4e09\u5143\u8868\u8fbe\u5f0f\u4e5f\u53ef\u4ee5\u7528\u6765\u8d4b\u503c\uff1a\r\n\r\n>>> y = 5\r\n>>> x = -1 if y < 0 else 1\r\n>>> x<\/pre>\n
4. with - as<\/strong><\/span><\/div>\n
with \u8fd9\u4e2a\u8bcd\u513f\uff0c\u82f1\u6587\u91cc\u9762\u4e0d\u96be\u7ffb\u8bd1\uff0c\u4f46\u5728 Python \u8bed\u6cd5\u4e2d\u600e\u4e48\u7ffb\u8bd1\uff0c\u6211\u8fd8\u771f\u60f3\u4e0d\u51fa\u6765\uff0c\u5927\u81f4\u4e0a\u662f\u4e00\u79cd\u4e0a\u4e0b\u6587\u7ba1\u7406\u534f\u8bae\u3002\u4f5c\u4e3a\u521d\u5b66\u8005\uff0c\u4e0d\u7528\u5173\u6ce8 with \u7684\u5404\u79cd\u65b9\u6cd5\u4ee5\u53ca\u673a\u5236\u5982\u4f55\uff0c\u53ea\u9700\u8981\u4e86\u89e3\u5b83\u7684\u5e94\u7528\u573a\u666f\u5c31\u53ef\u4ee5\u4e86\u3002with \u8bed\u53e5\u9002\u5408\u4e00\u4e9b\u4e8b\u5148\u9700\u8981\u51c6\u5907\uff0c\u4e8b\u540e\u9700\u8981\u5904\u7406\u7684\u4efb\u52a1\uff0c\u6bd4\u5982\uff0c\u6587\u4ef6\u64cd\u4f5c\uff0c\u9700\u8981\u5148\u6253\u5f00\u6587\u4ef6\uff0c\u64cd\u4f5c\u5b8c\u6210\u540e\u9700\u8981\u5173\u95ed\u6587\u4ef6\u3002\u5982\u679c\u4e0d\u4f7f\u7528with\uff0c\u6587\u4ef6\u64cd\u4f5c\u901a\u5e38\u5f97\u8fd9\u6837\uff1a<\/p>\n
fp = open(r\"D:\\CSDN\\Column\\temp\\mpmap.py\", 'r')\r\ntry:\r\ncontents = fp.readlines()\r\nfinally:\r\nfp.close()<\/pre>\n
\u5982\u679c\u4f7f\u7528 with - as\uff0c\u90a3\u5c31\u4f18\u96c5\u591a\u4e86\uff1a<\/p>\n
>>> with open(r\"D:\\CSDN\\Column\\temp\\mpmap.py\", 'r') as fp:\r\ncontents = fp.readlines()<\/pre>\n
5. \u5217\u8868\u63a8\u5bfc\u5f0f<\/strong><\/span><\/div>\n
\u5728\u5404\u79cd\u7a00\u5947\u53e4\u602a\u7684\u8bed\u6cd5\u4e2d\uff0c\u5217\u8868\u63a8\u5bfc\u5f0f\u7684\u4f7f\u7528\u9891\u7387\u5e94\u8be5\u65f6\u6700\u9ad8\u7684\uff0c\u5bf9\u4e8e\u4ee3\u7801\u7684\u7b80\u5316\u6548\u679c\u4e5f\u975e\u5e38\u660e\u663e\u3002\u6bd4\u5982\uff0c\u6c42\u5217\u8868\u5404\u5143\u7d20\u7684\u5e73\u65b9\uff0c\u901a\u5e38\u5e94\u8be5\u8fd9\u6837\u5199\uff08\u5f53\u7136\u4e5f\u6709\u5176\u4ed6\u5199\u6cd5\uff0c\u6bd4\u5982\u4f7f\u7528map\u51fd\u6570\uff09\uff1a<\/p>\n
>>> a = [1, 2, 3, 4, 5]\r\n>>> result = list()\r\n>>> for i in a:\r\nresult.append(i*i)\r\n\r\n>>> result\r\n[1, 4, 9, 16, 25]<\/pre>\n
\u5982\u679c\u4f7f\u7528\u5217\u8868\u63a8\u5bfc\u5f0f\uff0c\u770b\u8d77\u6765\u5c31\u8212\u670d\u591a\u4e86\uff1a<\/p>\n
>>> a = [1, 2, 3, 4, 5]\r\n>>> result = [i*i for i in a]\r\n>>> result\r\n[1, 4, 9, 16, 25]<\/pre>\n
\u4e8b\u5b9e\u4e0a\uff0c\u63a8\u5bfc\u5f0f\u4e0d\u4ec5\u652f\u6301\u5217\u8868\uff0c\u4e5f\u652f\u6301\u5b57\u5178\u3001\u96c6\u5408\u3001\u5143\u7ec4\u7b49\u5bf9\u8c61\u3002\u6709\u5174\u8da3\u7684\u8bdd\uff0c\u53ef\u4ee5\u81ea\u884c\u7814\u7a76\u3002\u6211\u6709\u4e00\u7bc7\u535a\u6587\u300a\u4e00\u884c Python \u4ee3\u7801\u80fd\u5b9e\u73b0\u4ec0\u4e48\u4e27\u5fc3\u75c5\u72c2\u7684\u529f\u80fd\uff1f\u300b\uff0c\u91cc\u9762\u7684\u4f8b\u5b50\uff0c\u90fd\u662f\u5217\u8868\u63a8\u5bfc\u5f0f\u5b9e\u73b0\u7684\u3002<\/p>\n
6. \u5217\u8868\u7d22\u5f15\u7684\u5404\u79cd\u9a9a\u64cd\u4f5c<\/strong><\/span><\/div>\n
Python \u5f15\u5165\u8d1f\u6574\u6570\u4f5c\u4e3a\u6570\u7ec4\u7684\u7d22\u5f15\uff0c\u8fd9\u7edd\u5bf9\u662f\u559c\u5927\u666e\u5954\u4e4b\u4e3e\u3002\u60f3\u60f3\u770b\uff0c\u5728C\/C++\u4e2d\uff0c\u60f3\u8981\u6570\u7ec4\u6700\u540e\u4e00\u4e2a\u5143\u7d20\uff0c\u5f97\u5148\u53d6\u5f97\u6570\u7ec4\u957f\u5ea6\uff0c\u51cf\u4e00\u4e4b\u540e\u505a\u7d22\u5f15\uff0c\u4e25\u91cd\u5f71\u54cd\u4e86\u601d\u7ef4\u7684\u8fde\u8d2f\u6027\u3002Python\u8bed\u8a00\u4e4b\u6240\u4ee5\u83b7\u5f97\u6210\u529f\uff0c\u6211\u4e2a\u4eba\u89c9\u5f97\uff0c\u5728\u8bf8\u591a\u56e0\u7d20\u91cc\u9762\uff0c\u5217\u8868\u64cd\u4f5c\u7684\u4fbf\u6377\u6027\u662f\u4e0d\u5bb9\u5ffd\u89c6\u7684\u4e00\u70b9\u3002\u8bf7\u770b\uff1a<\/p>\n
>>> a = [0, 1, 2, 3, 4, 5]\r\n>>> a[2:4]\r\n[2, 3]\r\n>>> a[3:]\r\n[3, 4, 5]\r\n>>> a[1:]\r\n[1, 2, 3, 4, 5]\r\n>>> a[:]\r\n[0, 1, 2, 3, 4, 5]\r\n>>> a[::2]\r\n[0, 2, 4]\r\n>>> a[1::2]\r\n[1, 3, 5]\r\n>>> a[-1]\r\n5\r\n>>> a[-2]\r\n4\r\n>>> a[1:-1]\r\n[1, 2, 3, 4]\r\n>>> a[::-1]\r\n[5, 4, 3, 2, 1, 0]<\/pre>\n
\u5982\u679c\u8bf4\uff0c\u8fd9\u4e9b\u4f60\u90fd\u5f88\u719f\u6089\uff0c\u4e5f\u7ecf\u5e38\u7528\uff0c\u90a3\u4e48\u63a5\u4e0b\u6765\u8fd9\u4e2a\u7528\u6cd5\uff0c\u4f60\u4e00\u5b9a\u4f1a\u611f\u89c9\u5f88\u795e\u5947\uff1a<\/p>\n
>>> a = [0, 1, 2, 3, 4, 5]\r\n>>> b = ['a', 'b']\r\n>>> a[2:2] = b\r\n>>> a\r\n[0, 1, 'a', 'b', 2, 3, 4, 5]\r\n>>> a[3:6] = b\r\n>>> a\r\n[0, 1, 'a', 'a', 'b', 4, 5]<\/pre>\n
7. lambda\u51fd\u6570<\/strong><\/span><\/div>\n
lambda \u542c\u8d77\u6765\u5f88\u9ad8\u5927\u4e0a\uff0c\u5176\u5b9e\u5c31\u662f\u533f\u540d\u51fd\u6570\uff08\u4e86\u89e3js\u7684\u540c\u5b66\u4e00\u5b9a\u5f88\u719f\u6089\u533f\u540d\u51fd\u6570\uff09\u3002\u533f\u540d\u51fd\u6570\u7684\u5e94\u7528\u573a\u666f\u662f\u4ec0\u4e48\u5462\uff1f\u5c31\u662f\u4ec5\u5728\u5b9a\u4e49\u533f\u540d\u51fd\u6570\u7684\u5730\u65b9\u4f7f\u7528\u8fd9\u4e2a\u51fd\u6570\uff0c\u5176\u4ed6\u5730\u65b9\u7528\u4e0d\u5230\uff0c\u6240\u4ee5\u5c31\u4e0d\u9700\u8981\u7ed9\u5b83\u53d6\u4e2a\u963f\u732b\u963f\u72d7\u4e4b\u7c7b\u7684\u540d\u5b57\u4e86\u3002\u4e0b\u9762\u662f\u4e00\u4e2a\u6c42\u548c\u7684\u533f\u540d\u51fd\u6570\uff0c\u8f93\u5165\u53c2\u6570\u6709\u4e24\u4e2a\uff0cx\u548cy\uff0c\u51fd\u6570\u4f53\u5c31\u662fx+y\uff0c\u7701\u7565\u4e86return\u5173\u952e\u5b57\u3002<\/p>\n
>>> lambda x,y: x+y\r\n<function <lambda> at 0x000001B2DE5BD598>\r\n>>> (lambda x,y: x+y)(3,4) # \u56e0\u4e3a\u533f\u540d\u51fd\u6570\u6ca1\u6709\u540d\u5b57\uff0c\u4f7f\u7528\u7684\u65f6\u5019\u8981\u7528\u62ec\u53f7\u628a\u5b83\u5305\u8d77\u6765<\/pre>\n
\u533f\u540d\u51fd\u6570\u4e00\u822c\u4e0d\u4f1a\u5355\u72ec\u4f7f\u7528\uff0c\u800c\u662f\u914d\u5408\u5176\u4ed6\u65b9\u6cd5\uff0c\u4e3a\u5176\u4ed6\u65b9\u6cd5\u63d0\u4f9b\u5185\u7f6e\u7684\u7b97\u6cd5\u6216\u5224\u65ad\u6761\u4ef6\u3002\u6bd4\u5982\uff0c\u4f7f\u7528\u6392\u5e8f\u51fd\u6570sorted\u5bf9\u591a\u7ef4\u6570\u7ec4\u6216\u8005\u5b57\u5178\u6392\u5e8f\u65f6\uff0c\u5c31\u53ef\u4ee5\u6307\u5b9a\u6392\u5e8f\u89c4\u5219\u3002<\/p>\n
>>> a = [{'name':'B', 'age':50}, {'name':'A', 'age':30}, {'name':'C', 'age':40}]\r\n>>> sorted(a, key=lambda x:x['name']) # \u6309\u59d3\u540d\u6392\u5e8f\r\n[{'name': 'A', 'age': 30}, {'name': 'B', 'age': 50}, {'name': 'C', 'age': 40}]\r\n>>> sorted(a, key=lambda x:x['age']) # \u6309\u5e74\u9f84\u6392\u5e8f\r\n[{'name': 'A', 'age': 30}, {'name': 'C', 'age': 40}, {'name': 'B', 'age': 50}]<\/pre>\n
\u518d\u4e3e\u4e00\u4e2a\u6570\u7ec4\u5143\u7d20\u6c42\u5e73\u65b9\u7684\u4f8b\u5b50\uff0c\u8fd9\u6b21\u7528map\u51fd\u6570\uff1a<\/p>\n
>>> a = [1,2,3]\r\n>>> for item in map(lambda x:x*x, a):\r\nprint(item, end=', ')\r\n\r\n1, 4, 9,<\/pre>\n
8. yield \u4ee5\u53ca\u751f\u6210\u5668\u548c\u8fed\u4ee3\u5668<\/strong><\/span><\/div>\n
yield \u8fd9\u8bcd\u513f\uff0c\u771f\u4e0d\u597d\u7ffb\u8bd1\uff0c\u7ffb\u8bcd\u5178\u4e5f\u6ca1\u7528\u3002\u6211\u5e72\u8106\u5c31\u8bfb\u4f5c\u201c\u4e00\u7231\u5f97\u201d\uff0c\u7b97\u662f\u5916\u6765\u8bcd\u6c47\u5427\u3002\u8981\u7406\u89e3 yield\uff0c\u5f97\u5148\u4e86\u89e3 generator\uff08\u751f\u6210\u5668\uff09\u3002\u8981\u4e86\u89e3generator\uff0c\u5f97\u5148\u77e5\u9053 iterator\uff08\u8fed\u4ee3\u5668\uff09\u3002\u54c8\u54c8\u54c8\uff0c\u7ed5\u6655\u4e86\u5427\uff1f\u7b97\u4e86\uff0c\u6211\u8fd8\u662f\u8bf4\u767d\u8bdd\u5427\u3002<\/p>\n
\u8bdd\u8bf4py2\u65f6\u4ee3\uff0crange()\u8fd4\u56de\u7684\u662flist\uff0c\u4f46\u5982\u679crange(10000000)\u7684\u8bdd\uff0c\u4f1a\u6d88\u8017\u5927\u91cf\u5185\u5b58\u8d44\u6e90\uff0c\u6240\u4ee5\uff0cpy2\u53c8\u641e\u4e86\u4e00\u4e2axrange()\u6765\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u3002py3\u5219\u53ea\u4fdd\u7559\u4e86xrange()\uff0c\u4f46\u5199\u4f5crange()\u3002xrange()\u8fd4\u56de\u7684\u5c31\u662f\u4e00\u4e2a\u8fed\u4ee3\u5668\uff0c\u5b83\u53ef\u4ee5\u50cflist\u90a3\u6837\u88ab\u904d\u5386\uff0c\u4f46\u53c8\u4e0d\u5360\u7528\u591a\u5c11\u5185\u5b58\u3002generator\uff08\u751f\u6210\u5668\uff09\u662f\u4e00\u79cd\u7279\u6b8a\u7684\u8fed\u4ee3\u5668\uff0c\u53ea\u80fd\u88ab\u904d\u5386\u4e00\u6b21\uff0c\u904d\u5386\u7ed3\u675f\uff0c\u5c31\u81ea\u52a8\u6d88\u5931\u4e86\u3002\u603b\u4e4b\uff0c\u4e0d\u7ba1\u662f\u8fed\u4ee3\u5668\u8fd8\u662f\u751f\u6210\u5668\uff0c\u90fd\u662f\u4e3a\u4e86\u907f\u514d\u4f7f\u7528list\uff0c\u4ece\u800c\u8282\u7701\u5185\u5b58\u3002\u90a3\u4e48\uff0c\u5982\u4f55\u5f97\u5230\u8fed\u4ee3\u5668\u548c\u751f\u6210\u5668\u5462\uff1f<\/p>\n
python\u5185\u7f6e\u4e86\u8fed\u4ee3\u51fd\u6570 iter\uff0c\u7528\u4e8e\u751f\u6210\u8fed\u4ee3\u5668\uff0c\u7528\u6cd5\u5982\u4e0b\uff1a<\/p>\n
>>> a = [1,2,3]\r\n>>> a_iter = iter(a)\r\n>>> a_iter\r\n<list_iterator object at 0x000001B2DE434BA8>\r\n>>> for i in a_iter:\r\nprint(i, end=', ')\r\n\r\n1, 2, 3,<\/pre>\n
yield \u5219\u662f\u7528\u4e8e\u6784\u9020\u751f\u6210\u5668\u7684\u3002\u6bd4\u5982\uff0c\u6211\u4eec\u8981\u5199\u4e00\u4e2a\u51fd\u6570\uff0c\u8fd4\u56de\u4ece0\u5230\u67d0\u6b63\u6574\u6570\u7684\u6240\u6709\u6574\u6570\u7684\u5e73\u65b9\uff0c\u4f20\u7edf\u7684\u4ee3\u7801\u5199\u6cd5\u662f\u8fd9\u6837\u7684\uff1a<\/p>\n
>>> def get_square(n):\r\nresult = list()\r\nfor i in range(n):\r\nresult.append(pow(i,2))\r\nreturn result\r\n\r\n>>> print(get_square(5))\r\n[0, 1, 4, 9, 16]<\/pre>\n
\u4f46\u662f\u5982\u679c\u8ba1\u7b971\u4ebf\u4ee5\u5185\u7684\u6240\u6709\u6574\u6570\u7684\u5e73\u65b9\uff0c\u8fd9\u4e2a\u51fd\u6570\u7684\u5185\u5b58\u5f00\u9500\u4f1a\u975e\u5e38\u5927\uff0c\u8fd9\u662f yield \u5c31\u53ef\u4ee5\u5927\u663e\u8eab\u624b\u4e86\uff1a<\/p>\n
>>> def get_square(n):\r\nfor i in range(n):\r\nyield(pow(i,2))\r\n\r\n>>> a = get_square(5)\r\n>>> a\r\n<generator object get_square at 0x000001B2DE5CACF0>\r\n>>> for i in a:\r\nprint(i, end=', ')\r\n\r\n0, 1, 4, 9, 16,<\/pre>\n
\u5982\u679c\u518d\u6b21\u904d\u5386\uff0c\u5219\u4e0d\u4f1a\u6709\u8f93\u51fa\u4e86\u3002<\/p>\n
9. \u88c5\u9970\u5668<\/strong><\/span><\/div>\n
\u521a\u5f04\u660e\u767d\u8fed\u4ee3\u5668\u548c\u751f\u6210\u5668\uff0c\u8fd9\u53c8\u6765\u4e2a\u88c5\u9970\u5668\uff0cPython \u548b\u8fd9\u4e48\u591a\u5668\u5462\uff1f\u7684\u786e\uff0cPython \u4e3a\u6211\u4eec\u63d0\u4f9b\u4e86\u5f88\u591a\u7684\u6b66\u5668\uff0c\u88c5\u9970\u5668\u5c31\u662f\u6700\u6709\u529b\u7684\u6b66\u5668\u4e4b\u4e00\u3002\u88c5\u9970\u5668\u5f88\u5f3a\u5927\uff0c\u6211\u5728\u8fd9\u91cc\u5c1d\u8bd5\u4ece\u9700\u6c42\u7684\u89d2\u5ea6\uff0c\u7528\u4e00\u4e2a\u7b80\u5355\u7684\u4f8b\u5b50\uff0c\u8bf4\u660e\u88c5\u9970\u5668\u7684\u4f7f\u7528\u65b9\u6cd5\u548c\u5236\u9020\u5de5\u827a\u3002<\/p>\n
\u5047\u5982\u6211\u4eec\u9700\u8981\u5b9a\u4e49\u5f88\u591a\u4e2a\u51fd\u6570\uff0c\u5728\u6bcf\u4e2a\u51fd\u6570\u8fd0\u884c\u7684\u65f6\u5019\u8981\u663e\u793a\u8fd9\u4e2a\u51fd\u6570\u7684\u8fd0\u884c\u65f6\u957f\uff0c\u89e3\u51b3\u65b9\u6848\u6709\u5f88\u591a\u3002\u6bd4\u5982\uff0c\u53ef\u4ee5\u5728\u8c03\u7528\u6bcf\u4e2a\u51fd\u6570\u4e4b\u524d\u8bfb\u4e00\u4e0b\u65f6\u95f4\u6233\uff0c\u6bcf\u4e2a\u51fd\u6570\u8fd0\u884c\u7ed3\u675f\u540e\u518d\u8bfb\u4e00\u4e0b\u65f6\u95f4\u6233\uff0c\u6c42\u5dee\u5373\u53ef\uff1b\u4e5f\u53ef\u4ee5\u5728\u6bcf\u4e2a\u51fd\u6570\u4f53\u5185\u7684\u5f00\u59cb\u548c\u7ed3\u675f\u4f4d\u7f6e\u4e0a\u8bfb\u65f6\u95f4\u6233\uff0c\u6700\u540e\u6c42\u5dee\u3002\u4e0d\u8fc7\uff0c\u8fd9\u4e24\u4e2a\u65b9\u6cd5\uff0c\u90fd\u6ca1\u6709\u4f7f\u7528\u88c5\u9970\u5668\u90a3\u4e48\u7b80\u5355\u3001\u4f18\u96c5\u3002\u4e0b\u9762\u7684\u4f8b\u5b50\uff0c\u5f88\u597d\u5730\u5c55\u793a\u4e86\u8fd9\u4e00\u70b9\u3002<\/p>\n
>>> import time\r\n>>> def timer(func):\r\ndef wrapper(*args,**kwds):\r\nt0 = time.time()\r\nfunc(*args,**kwds)\r\nt1 = time.time()\r\nprint('\u8017\u65f6%0.3f'%(t1-t0,))\r\nreturn wrapper\r\n\r\n>>> @timer\r\ndef do_something(delay):\r\nprint('\u51fd\u6570do_something\u5f00\u59cb')\r\ntime.sleep(delay)\r\nprint('\u51fd\u6570do_something\u7ed3\u675f')\r\n\r\n>>> do_something(3)\r\n\u51fd\u6570do_something\u5f00\u59cb\r\n\u51fd\u6570do_something\u7ed3\u675f\r\n\u8017\u65f63.077<\/pre>\n
timer() \u662f\u6211\u4eec\u5b9a\u4e49\u7684\u88c5\u9970\u5668\u51fd\u6570\uff0c\u4f7f\u7528@\u628a\u5b83\u9644\u52a0\u5728\u4efb\u4f55\u4e00\u4e2a\u51fd\u6570\uff08\u6bd4\u5982do_something\uff09\u5b9a\u4e49\u4e4b\u524d\uff0c\u5c31\u7b49\u4e8e\u628a\u65b0\u5b9a\u4e49\u7684\u51fd\u6570\uff0c\u5f53\u6210\u4e86\u88c5\u9970\u5668\u51fd\u6570\u7684\u8f93\u5165\u53c2\u6570\u3002\u8fd0\u884c do_something() \u51fd\u6570\uff0c\u53ef\u4ee5\u7406\u89e3\u4e3a\u6267\u884c\u4e86timer(do_something) \u3002\u7ec6\u8282\u867d\u7136\u590d\u6742\uff0c\u4e0d\u8fc7\u8fd9\u4e48\u7406\u89e3\u4e0d\u4f1a\u504f\u5dee\u592a\u5927\uff0c\u4e14\u66f4\u6613\u4e8e\u628a\u63e1\u88c5\u9970\u5668\u7684\u5236\u9020\u548c\u4f7f\u7528\u3002<\/p>\n
10. \u5de7\u7528\u65ad\u8a00assert<\/strong><\/span><\/div>\n
\u6240\u8c13\u65ad\u8a00\uff0c\u5c31\u662f\u58f0\u660e\u8868\u8fbe\u5f0f\u7684\u5e03\u5c14\u503c\u5fc5\u987b\u4e3a\u771f\u7684\u5224\u5b9a\uff0c\u5426\u5219\u5c06\u89e6\u53d1 AssertionError \u5f02\u5e38\u3002\u4e25\u683c\u6765\u8bb2\uff0cassert\u662f\u8c03\u8bd5\u624b\u6bb5\uff0c\u4e0d\u5b9c\u4f7f\u7528\u5728\u751f\u4ea7\u73af\u5883\u4e2d\uff0c\u4f46\u8fd9\u4e0d\u5f71\u54cd\u6211\u4eec\u7528\u65ad\u8a00\u6765\u5b9e\u73b0\u4e00\u4e9b\u7279\u5b9a\u529f\u80fd\uff0c\u6bd4\u5982\uff0c\u8f93\u5165\u53c2\u6570\u7684\u683c\u5f0f\u3001\u7c7b\u578b\u9a8c\u8bc1\u7b49\u3002<\/p>\n
>>> def i_want_to_sleep(delay):\r\nassert(isinstance(delay, (int,float))), '\u51fd\u6570\u53c2\u6570\u5fc5\u987b\u4e3a\u6574\u6570\u6216\u6d6e\u70b9\u6570'\r\nprint('\u5f00\u59cb\u7761\u89c9')\r\ntime.sleep(delay)\r\nprint('\u7761\u9192\u4e86')\r\n\r\n>>> i_want_to_sleep(1.1)\r\n\u5f00\u59cb\u7761\u89c9\r\n\u7761\u9192\u4e86\r\n>>> i_want_to_sleep(2)\r\n\u5f00\u59cb\u7761\u89c9\r\n\u7761\u9192\u4e86\r\n>>> i_want_to_sleep('2')\r\nTraceback (most recent call last):\r\nFile \"<pyshell#247>\", line 1, in <module>\r\ni_want_to_sleep('2')\r\nFile \"<pyshell#244>\", line 2, in i_want_to_sleep\r\nassert(isinstance(delay, (int,float))), '\u51fd\u6570\u53c2\u6570\u5fc5\u987b\u4e3a\u6574\u6570\u6216\u6d6e\u70b9\u6570'\r\nAssertionError: \u51fd\u6570\u53c2\u6570\u5fc5\u987b\u4e3a\u6574\u6570\u6216\u6d6e\u70b9\u6570<\/pre>\n","protected":false},"excerpt":{"rendered":"
\u4ec0\u4e48\uff1f\u4e0d\u662f if \u548c else \u624d\u662f\u539f\u914d\u5417\uff1fNo\uff0c\u4f60\u53ef\u80fd\u4e0d\u77e5\u9053\uff0celse \u662f\u4e2a\u811a\u8e29\u4e24\u53ea\u8239\u7684\u5bb6\u4f19\uff0cfor \u548c e […]<\/p>\n","protected":false},"author":643,"featured_media":164002,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[55],"tags":[],"class_list":["post-163996","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-thread"],"acf":[],"_links":{"self":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts\/163996","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/users\/643"}],"replies":[{"embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/comments?post=163996"}],"version-history":[{"count":8,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts\/163996\/revisions"}],"predecessor-version":[{"id":164015,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/posts\/163996\/revisions\/164015"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/media\/164002"}],"wp:attachment":[{"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/media?parent=163996"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/categories?post=163996"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lrxjmw.cn\/wp-json\/wp\/v2\/tags?post=163996"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}