{"id":189,"date":"2020-04-28T15:55:24","date_gmt":"2020-04-28T07:55:24","guid":{"rendered":"http:\/\/8.154.33.202\/?p=189"},"modified":"2020-04-28T15:55:24","modified_gmt":"2020-04-28T07:55:24","slug":"python%e5%86%85%e7%bd%ae%e5%87%bd%e6%95%b0%ef%bc%88%e4%b8%89%ef%bc%89eval%e3%80%81exec","status":"publish","type":"post","link":"http:\/\/8.154.33.202\/?p=189","title":{"rendered":"python\u5185\u7f6e\u51fd\u6570\uff08\u4e09\uff09eval\u3001exec"},"content":{"rendered":"\n

python\u4e2d\u8fd9\u4e24\u4e2a\u5185\u7f6e\u7684\u51fd\u6570eval\u548cexec\u90fd\u53ef\u4ee5\u6267\u884cstr\u5f62\u5f0f\u7684python\u8868\u8fbe\u5f0f\uff0c\u6bd4\u5982\u8bf4”print(a + b)” \u3002\u6709\u65f6\u5019\u53ef\u4ee5\u6d3e\u4e0a\u7528\u573a\u3002<\/p>\n\n\n\n

eval\u51fd\u6570\u5f62\u5f0f<\/p>\n\n\n\n

eval(source, globals=None, locals=None)<\/pre>\n\n\n\n
\u5176\u4e2dgobals\u548clocals\u5206\u522b\u8868\u793a\u5168\u5c40\u547d\u540d\u7a7a\u95f4\u548c\u5c40\u90e8\u547d\u540d\u7a7a\u95f4\uff0c\u5fc5\u987b\u662fdict\u5f62\u5f0f\u3002\u5982\u679c\u4e0d\u63d0\u4f9b\u5219\u4f7f\u7528\u5f53\u524d\u8c03\u7528\u73af\u5883\u4e0b\u7684\u5168\u5c40\u547d\u540d\u7a7a\u95f4\u548c\u5c40\u90e8\u547d\u540d\u7a7a\u95f4\u3002eval\u7684\u8fd4\u56de\u503c\u5c31\u662f\u5176\u4e2d\u8868\u8fbe\u5f0f\u7684\u8fd4\u56de\u503c\u3002\u6ce8\u610feval\u4e2d\u7684\u8868\u8fbe\u5f0f\u4e0d\u80fd\u662f\u8d4b\u503c\u8868\u8fbe\u5f0f\uff01\uff01\uff01<\/p>\n\n\n\n
a = 10\ndef foo():\n    b = 12\n    c = eval(\"a+b\")\n    print(\"c:\",c)\n    d = eval(\"a+b\",{\"a\":1,\"b\":2})\n    print(\"d:\",d)\n    e = eval(\"a+b\",{\"a\":1,\"b\":2},{\"b\":3})\n    print(\"e:\",e)\n    f = eval(\"print(a+b)\")\n    print(\"f:\",f)\n\nfoo()<\/pre>\n\n\n\n
\u7ed3\u679c\u4e3a<\/p>\n\n\n\n
c: 22\nd: 3\ne: 4\n22\nf: None<\/pre>\n\n\n\n
exec\u51fd\u6570\u5f62\u5f0f<\/p>\n\n\n\n
exec(source, globals=None, locals=None)<\/pre>\n\n\n\n
\u5f62\u5f0f\u4e0a\u540ceval\u51fd\u6570\u4e00\u6837\u3002exec\u51fd\u6570\u4e2d\u53ef\u4ee5\u662f\u8d4b\u503c\u8868\u8fbe\u5f0f\u3002\u4f46exec\u4e0eeval\u6700\u4e3b\u8981\u7684\u533a\u522b\u662f\u5b83\u53ef\u4ee5\u8fd0\u884c\u4ee3\u7801\u6bb5\uff0c\u800ceval\u4e2d\u53ea\u80fd\u662f\u5355\u4e2a\u8868\u8fbe\u5f0f\u3002 \u53e6\u5916exec\u51fd\u6570\u8fd4\u56de\u503c\u6c38\u8fdc\u662fNone\uff01 <\/p>\n\n\n\n
snippet = \n\"\"\"\na = 1\nb = 2\nc = a+b\nprint(c)\nprint(\"this is a code snippet\")\n\"\"\" \n\na = 10\ndef foo():\n    b = 12\n    c = exec(\"a+b\")\n    print(\"c:\",c)\n    d = exec(\"d=a+b\\nprint('d:',d)\")\n    exec(snippet)\n\nfoo()<\/pre>\n\n\n\n
\u7ed3\u679c\u4e3a<\/p>\n\n\n\n
c: None\nd: 22\n3\nthis is a code snippet<\/pre>\n","protected":false},"excerpt":{"rendered":"
python\u4e2d\u8fd9\u4e24\u4e2a\u5185\u7f6e\u7684\u51fd\u6570eval\u548cexec\u90fd\u53ef\u4ee5\u6267\u884cstr\u5f62\u5f0f\u7684python\u8868\u8fbe\u5f0f\uff0c\u6bd4\u5982\u8bf4” … <\/p>\n
\u7ee7\u7eed\u9605\u8bfb\u201cpython\u5185\u7f6e\u51fd\u6570\uff08\u4e09\uff09eval\u3001exec\u201d<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-189","post","type-post","status-publish","format-standard","hentry","category-python"],"_links":{"self":[{"href":"http:\/\/8.154.33.202\/index.php?rest_route=\/wp\/v2\/posts\/189"}],"collection":[{"href":"http:\/\/8.154.33.202\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/8.154.33.202\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/8.154.33.202\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/8.154.33.202\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=189"}],"version-history":[{"count":2,"href":"http:\/\/8.154.33.202\/index.php?rest_route=\/wp\/v2\/posts\/189\/revisions"}],"predecessor-version":[{"id":193,"href":"http:\/\/8.154.33.202\/index.php?rest_route=\/wp\/v2\/posts\/189\/revisions\/193"}],"wp:attachment":[{"href":"http:\/\/8.154.33.202\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=189"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/8.154.33.202\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=189"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/8.154.33.202\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=189"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}