{"id":169678,"date":"2022-04-15T08:47:22","date_gmt":"2022-04-15T00:47:22","guid":{"rendered":"http:\/\/www.idc.net\/help\/169678\/"},"modified":"2022-04-15T08:47:22","modified_gmt":"2022-04-15T00:47:22","slug":"%e5%90%8e%e6%b5%aa%e4%ba%91python%e6%95%99%e7%a8%8b%ef%bc%9apython%e8%bf%ad%e4%bb%a3%e5%99%a8%e5%a6%82%e4%bd%95%e5%ae%9e%e7%8e%b0","status":"publish","type":"post","link":"https:\/\/idc.net\/help\/169678\/","title":{"rendered":"\u540e\u6d6a\u4e91Python\u6559\u7a0b\uff1apython\u8fed\u4ee3\u5668\u5982\u4f55\u5b9e\u73b0"},"content":{"rendered":"

<\/p>\n

\u8fed\u4ee3\u662fPython\u6700\u5f3a\u5927\u7684\u529f\u80fd\u4e4b\u4e00\uff0c\u662f\u8bbf\u95ee\u96c6\u5408\u5143\u7d20\u7684\u4e00\u79cd\u65b9\u5f0f\u3002\u8fed\u4ee3\u5668\u662f\u4e00\u4e2a\u53ef\u4ee5\u8bb0\u4f4f\u904d\u5386\u7684\u4f4d\u7f6e\u7684\u5bf9\u8c61\u3002\u8fed\u4ee3\u5668\u5bf9\u8c61\u4ece\u96c6\u5408\u7684\u7b2c\u4e00\u4e2a\u5143\u7d20\u5f00\u59cb\u8bbf\u95ee\uff0c\u76f4\u5230\u6240\u6709\u7684\u5143\u7d20\u88ab\u8bbf\u95ee\u5b8c\u7ed3\u675f\u3002\u8fed\u4ee3\u5668\u53ea\u80fd\u5f80\u524d\u4e0d\u4f1a\u540e\u9000\u3002<\/p>\n

\u8fed\u4ee3\u5668\u6709\u4e24\u4e2a\u57fa\u672c\u7684\u65b9\u6cd5\uff1aiter() \u548c next()\u3002<\/p>\n

\u5b57\u7b26\u4e32\uff0c\u5217\u8868\u6216\u5143\u7ec4\u5bf9\u8c61\u90fd\u53ef\u7528\u4e8e\u521b\u5efa\u8fed\u4ee3\u5668\uff1a<\/p>\n

\u5b9e\u4f8b(Python 3.0+)<\/p>\n

>>> list=[1,2,3,4]\n>>> it = iter(list)    # \u521b\u5efa\u8fed\u4ee3\u5668\u5bf9\u8c61\n>>> print (next(it))   # \u8f93\u51fa\u8fed\u4ee3\u5668\u7684\u4e0b\u4e00\u4e2a\u5143\u7d20\n1\n>>> print (next(it))\n2\n>>><\/pre>\n
\u8fed\u4ee3\u5668\u5bf9\u8c61\u53ef\u4ee5\u4f7f\u7528\u5e38\u89c4for\u8bed\u53e5\u8fdb\u884c\u904d\u5386\uff1a<\/strong><\/p>\n
\u5b9e\u4f8b(Python 3.0+)<\/p>\n
#!\/usr\/bin\/python3\n \nlist=[1,2,3,4]\nit = iter(list)    # \u521b\u5efa\u8fed\u4ee3\u5668\u5bf9\u8c61\nfor x in it:\n    print (x, end=\" \")<\/pre>\n
\u6267\u884c\u4ee5\u4e0a\u7a0b\u5e8f\uff0c\u8f93\u51fa\u7ed3\u679c\u5982\u4e0b\uff1a<\/p>\n
1 2 3 4<\/pre>\n
\u76f8\u5173\u63a8\u8350\uff1a\u300aPython\u57fa\u7840\u6559\u7a0b\u300b<\/p>\n
\u4e5f\u53ef\u4ee5\u4f7f\u7528 next() \u51fd\u6570\uff1a<\/strong><\/p>\n
\u5b9e\u4f8b(Python 3.0+)<\/p>\n
#!\/usr\/bin\/python3\nimport sys         # \u5f15\u5165 sys \u6a21\u5757\n \nlist=[1,2,3,4]\nit = iter(list)    # \u521b\u5efa\u8fed\u4ee3\u5668\u5bf9\u8c61\n \nwhile True:\n    try:\n        print (next(it))\n    except StopIteration:\n        sys.exit()<\/pre>\n
\u6267\u884c\u4ee5\u4e0a\u7a0b\u5e8f\uff0c\u8f93\u51fa\u7ed3\u679c\u5982\u4e0b\uff1a<\/p>\n
1\n2\n3\n4<\/pre>\n
\u521b\u5efa\u4e00\u4e2a\u8fed\u4ee3\u5668<\/strong><\/p>\n
\u628a\u4e00\u4e2a\u7c7b\u4f5c\u4e3a\u4e00\u4e2a\u8fed\u4ee3\u5668\u4f7f\u7528\u9700\u8981\u5728\u7c7b\u4e2d\u5b9e\u73b0\u4e24\u4e2a\u65b9\u6cd5 __iter__() \u4e0e __next__() \u3002<\/p>\n
\u5982\u679c\u4f60\u5df2\u7ecf\u4e86\u89e3\u7684\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b\uff0c\u5c31\u77e5\u9053\u7c7b\u90fd\u6709\u4e00\u4e2a\u6784\u9020\u51fd\u6570\uff0cPython \u7684\u6784\u9020\u51fd\u6570\u4e3a __init__(), \u5b83\u4f1a\u5728\u5bf9\u8c61\u521d\u59cb\u5316\u7684\u65f6\u5019\u6267\u884c\u3002<\/p>\n
__iter__() \u65b9\u6cd5\u8fd4\u56de\u4e00\u4e2a\u7279\u6b8a\u7684\u8fed\u4ee3\u5668\u5bf9\u8c61\uff0c \u8fd9\u4e2a\u8fed\u4ee3\u5668\u5bf9\u8c61\u5b9e\u73b0\u4e86 __next__() \u65b9\u6cd5\u5e76\u901a\u8fc7 StopIteration \u5f02\u5e38\u6807\u8bc6\u8fed\u4ee3\u7684\u5b8c\u6210\u3002<\/p>\n
__next__() \u65b9\u6cd5\uff08Python 2 \u91cc\u662f next()\uff09\u4f1a\u8fd4\u56de\u4e0b\u4e00\u4e2a\u8fed\u4ee3\u5668\u5bf9\u8c61\u3002<\/p>\n
\u521b\u5efa\u4e00\u4e2a\u8fd4\u56de\u6570\u5b57\u7684\u8fed\u4ee3\u5668\uff0c\u521d\u59cb\u503c\u4e3a 1\uff0c\u9010\u6b65\u9012\u589e 1\uff1a<\/p>\n
\u5b9e\u4f8b(Python 3.0+)<\/p>\n
class MyNumbers:\n  def __iter__(self):\n    self.a = 1\n    return self\n \n  def __next__(self):\n    x = self.a\n    self.a += 1\n    return x\n \nmyclass = MyNumbers()\nmyiter = iter(myclass)\n \nprint(next(myiter))\nprint(next(myiter))\nprint(next(myiter))\nprint(next(myiter))\nprint(next(myiter))<\/pre>\n
\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n
1\n2\n3\n4\n5<\/pre>\n
StopIteration<\/strong><\/p>\n
StopIteration \u5f02\u5e38\u7528\u4e8e\u6807\u8bc6\u8fed\u4ee3\u7684\u5b8c\u6210\uff0c\u9632\u6b62\u51fa\u73b0\u5faa\u73af\u7684\u60c5\u51b5\uff0c\u5728 __next__() \u65b9\u6cd5\u4e2d\u6211\u4eec\u53ef\u4ee5\u8bbe\u7f6e\u5728\u5b8c\u6210\u6307\u5b9a\u5faa\u73af\u6b21\u6570\u540e\u89e6\u53d1 StopIteration \u5f02\u5e38\u6765\u7ed3\u675f\u8fed\u4ee3\u3002<\/p>\n
\u5728 20 \u6b21\u8fed\u4ee3\u540e\u505c\u6b62\u6267\u884c\uff1a<\/p>\n
\u5b9e\u4f8b(Python 3.0+)<\/p>\n
class MyNumbers:\n  def __iter__(self):\n    self.a = 1\n    return self\n \n  def __next__(self):\n    if self.a <= 20:\n      x = self.a\n      self.a += 1\n      return x\n    else:\n      raise StopIteration\n \nmyclass = MyNumbers()\nmyiter = iter(myclass)\n \nfor x in myiter:\n  print(x)<\/pre>\n
\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n
1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n11\n12\n13\n14\n15\n16\n17\n18\n19\n20<\/pre>\n","protected":false},"excerpt":{"rendered":"
\u8fed\u4ee3\u662fPython\u6700\u5f3a\u5927\u7684\u529f\u80fd\u4e4b\u4e00\uff0c\u662f\u8bbf\u95ee\u96c6\u5408\u5143\u7d20\u7684\u4e00\u79cd\u65b9\u5f0f\u3002\u8fed\u4ee3\u5668\u662f\u4e00\u4e2a\u53ef\u4ee5\u8bb0\u4f4f\u904d\u5386\u7684\u4f4d\u7f6e\u7684\u5bf9\u8c61\u3002\u8fed\u4ee3\u5668\u5bf9\u8c61 […]<\/p>\n","protected":false},"author":1,"featured_media":169679,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[182397],"tags":[],"class_list":["post-169678","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-python"],"_links":{"self":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts\/169678","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/comments?post=169678"}],"version-history":[{"count":0,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts\/169678\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/media\/169679"}],"wp:attachment":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/media?parent=169678"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/categories?post=169678"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/tags?post=169678"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}