{"id":36,"date":"2016-11-20T12:46:45","date_gmt":"2016-11-20T12:46:45","guid":{"rendered":"http:\/\/python.wp.w3.pt\/?p=36"},"modified":"2016-11-20T16:28:25","modified_gmt":"2016-11-20T16:28:25","slug":"funcoes-predefinidas","status":"publish","type":"post","link":"http:\/\/python.w3.pt\/?p=36","title":{"rendered":"Fun\u00e7\u00f5es predefinidas"},"content":{"rendered":"<p>Para al\u00e9m do <a href=\"https:\/\/docs.python.org\/2\/reference\/index.html\">manual de refer\u00eancia<\/a>, que \u00e9 relativamente \u00e1rido nalguns cap\u00edtulos, o Python tem um manual sobre a <a href=\"https:\/\/docs.python.org\/2\/library\/index.html\">Biblioteca Standard<\/a>, que come\u00e7a por apresentar as <a href=\"https:\/\/docs.python.org\/2\/library\/functions.html#\">fun\u00e7\u00f5es predefinidas<\/a> da linguagem.<\/p>\n<p>A fun\u00e7\u00e3o <em>abs()<\/em> calcula o valor absoluto de inteiros, reais e complexos.<\/p>\n<pre>\r\n>>> abs(-3)\r\n3\r\n>>> abs(-7.5)\r\n7.5\r\n>>> abs(3+4j)\r\n5.0\r\n<\/pre>\n<p>A fun\u00e7\u00e3o <em>all()<\/em> verifica se todos os elementos de um iter\u00e1vel s\u00e3o verdade.<br \/>\nA fun\u00e7\u00e3o <em>any()<\/em> verifica se algum elemento de um iter\u00e1vel \u00e9 verdade.<\/p>\n<pre>\r\n>>> all([1,0]) &#160;&#160;&#160;# array composto por 1 e 0\r\nFalse\r\n>>> all([1,4]) &#160;&#160;&#160;# array composto por 1 e 4\r\nTrue\r\n>>> any([1,0])\r\nTrue\r\n>>> any([0,0,False])\r\nFalse\r\n>>> any([True,False])\r\nTrue\r\n<\/pre>\n<p>O tipo abstrato <em>basestring()<\/em> n\u00e3o pode ser instanciado, \u00e9 a superclasse de <em>str<\/em> e <em>unicode<\/em>, mas pode ser usado para testar se um objeto \u00e9 do tipo <em>str<\/em> ou <em>unicode<\/em>.<\/p>\n<pre>\r\n>>> isinstance(\"Ola\", basestring)\r\nTrue\r\n>>> isinstance(\"Ol\u00e1 Mundo\", basestring)\r\nTrue\r\n>>> isinstance(123, basestring)\r\nFalse\r\n<\/pre>\n<p>A fun\u00e7\u00e3o bin() devolve uma string com a representa\u00e7\u00e3o bin\u00e1ria de um inteiro. Ainda ningu\u00e9m desafiou o guru do Python a mostrar a representa\u00e7\u00e3o bin\u00e1ria de um real? Em C pode ser feita assim: <\/p>\n<pre>float x = 3.5;\r\nprintf(\"%X\", *(int*)&x);<\/pre>\n<p>bool() avalia um objeto como booleano.<\/p>\n<pre>\r\n>>> bin(123)\r\n'0b1111011'\r\n>>> bool(2)\r\nTrue\r\n>>> bool(0)\r\nFalse\r\n>>> bool()\r\nFalse\r\n<\/pre>\n<p>A fun\u00e7\u00e3o <em>bytearray()<\/em> devolve o array de bytes que comp\u00f5em uma string. Se a string estiver em unicode, \u00e9 necess\u00e1rio passar a codifica\u00e7\u00e3o como par\u00e2metro. Ver <a href=\"https:\/\/docs.python.org\/2\/library\/functions.html#bytearray\">documenta\u00e7\u00e3o<\/a>.<\/p>\n<pre>\r\n>>> bytearray(\"abc\")\r\nbytearray(b'abc')\r\n>>>\r\n>>> s = \"Ol\u00e1 Mundo\"\r\n>>> \":\".join(\"{:02x}\".format(ord(c)) for c in s)\r\n'4f:6c:e1:20:4d:75:6e:64:6f'\r\n>>>\r\n>>> s = bytearray(\"Ol\u00e1 Mundo\")\r\n>>> \":\".join(\"{:02x}\".format(c) for c in s)\r\n'4f:6c:e1:20:4d:75:6e:64:6f'\r\n<\/pre>\n<p>Mais fun\u00e7\u00f5es no pr\u00f3ximo artigo.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Para al\u00e9m do manual de refer\u00eancia, que \u00e9 relativamente \u00e1rido nalguns cap\u00edtulos, o Python tem um manual sobre a Biblioteca Standard, que come\u00e7a por apresentar as fun\u00e7\u00f5es predefinidas da linguagem. A fun\u00e7\u00e3o abs() calcula o valor absoluto de inteiros, reais e complexos. >>> abs(-3) 3 >>> abs(-7.5) 7.5 >>> abs(3+4j) 5.0 A fun\u00e7\u00e3o all() verifica &hellip; <\/p>\n<p class=\"link-more\"><a href=\"http:\/\/python.w3.pt\/?p=36\" class=\"more-link\">Continuar a ler <span class=\"screen-reader-text\">&#8220;Fun\u00e7\u00f5es predefinidas&#8221;<\/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":[1],"tags":[],"_links":{"self":[{"href":"http:\/\/python.w3.pt\/index.php?rest_route=\/wp\/v2\/posts\/36"}],"collection":[{"href":"http:\/\/python.w3.pt\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/python.w3.pt\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/python.w3.pt\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/python.w3.pt\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=36"}],"version-history":[{"count":6,"href":"http:\/\/python.w3.pt\/index.php?rest_route=\/wp\/v2\/posts\/36\/revisions"}],"predecessor-version":[{"id":42,"href":"http:\/\/python.w3.pt\/index.php?rest_route=\/wp\/v2\/posts\/36\/revisions\/42"}],"wp:attachment":[{"href":"http:\/\/python.w3.pt\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=36"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/python.w3.pt\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=36"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/python.w3.pt\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=36"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}