python中的代码块是什么?

时间:2018-04-29 04:29:07

标签: python

我查了定义,但所有这些看起来都令人困惑。对不起,我是一个非常新的人,如果有更简单的方法,我会这样做

3 个答案:

答案 0 :(得分:2)

代码块是一组将作为一个单元运行的语句。

例如:

if (condition):
    #statement1
    #statement2
    #statement3
else:
    #statement4
    #statement5
    #statement6

您会发现语句1,2,3 具有相同的缩进,因此属于同一个块。 类似的陈述4,5,6 是另一个块。

您可以参考:

https://docs.python.org/3/reference/executionmodel.html

http://www.peachpit.com/articles/article.aspx?p=1312792&seqNum=3

答案 1 :(得分:1)

当我们说“阻止”时,我们指的是嵌套在另一个语法元素(如方法或函数)或package com.techshala.ramyakmehra.flashsalehelper; public class MainActivity extends AppCompatActivity { WebView wv; @Override public void onBackPressed() { if (wv.canGoBack()) { wv.goBack(); ; } else { super.onBackPressed(); ; } } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); wv = ((WebView) findViewById(R.id.webview)); wv.setFocusable(true); wv.setFocusableInTouchMode(true); wv.getSettings().setAppCacheEnabled(true); wv.getSettings().setUserAgentString("Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36"); wv.getSettings().setJavaScriptEnabled(true); wv.getSettings().setBuiltInZoomControls(true); wv.getSettings().setUseWideViewPort(true); wv.setScrollbarFadingEnabled(false); if (Build.VERSION.SDK_INT >= 19) { WebView.setWebContentsDebuggingEnabled(true); CookieManager.getInstance().setAcceptCookie(true); } wv.loadUrl("https://flipkart.com"); wv.setWebViewClient(new WebViewClient()); } public void onPageFinished(WebView paramWebView, String paramString) { if (Build.VERSION.SDK_INT >= 19) { WebView.setWebContentsDebuggingEnabled(true); CookieManager.getInstance().setAcceptCookie(true); } onPageFinished(paramWebView, paramString); { onPageFinished(paramWebView, paramString); if (paramString.toLowerCase().equals("https://www.flipkart.com/account/login?ret=https%3A%2F%2Fwww.flipkart.com%2Faccount")) { } onPageFinished(paramWebView, paramString); if (paramString.toLowerCase().equals("https://www.flipkart.com/account/")) { wv.loadUrl("https://www.flipkart.com/operon-b57d-dew-bp-monitor/p/itmex9bqpzh4hdsn?pid=BPMEX9BQGRZHWXYT&lid=LSTBPMEX9BQGRZHWXYTWOV79S&marketplace=FLIPKART&srno=b_1_1&otracker=hp_omu_Deals%20of%20the%20Day_1_From%20%E2%82%B9%20749_5F6E9K1E29R8_0&fm=neo/merchandising&iid=5b332980-eab1-4e62-9cff-6946b49e71e4.BPMEX9BQGRZHWXYT.SEARCH&ppt=Store%20Browse&ppn=Search%20Page&ssid=kz8qhsw55s0000001524827753408"); }onPageFinished(paramWebView, paramString); if (paramString.toLowerCase().contains("/p/")) { wv.loadUrl("javascript: if ((document.getElementsByClassName('_2AkmmA _2Npkh4 _2MWPVK RpigiU') .length > 0) || (document.getElementsByClassName('_2AkmmA _2Npkh4 _2kuvG8 _7UHT_c') .length > 0)) { var listId = document.getElementsByClassName(\"niH0FQ _36Fcw_\")[0].childNodes[0].getAttribute(\"id\") .split('_')[1]; var hiddenEids = document.createElement(\"input\"); hiddenEids.setAttribute(\"type\", \"hidden\"); hiddenEids.setAttribute(\"name\", \"eids\"); hiddenEids.setAttribute(\"value\", listId); var hiddenOtracker = document.createElement(\"input\"); hiddenOtracker.setAttribute(\"type\", \"hidden\"); hiddenOtracker.setAttribute(\"name\", \"otracker\"); hiddenOtracker.setAttribute(\"value\", \"\"); var hiddenDomain = document.createElement(\"input\"); hiddenDomain.setAttribute(\"type\", \"hidden\"); hiddenDomain.setAttribute(\"name\", \"domain\"); hiddenDomain.setAttribute(\"value\", \"physical\"); var formtag = document.createElement(\"form\"); formtag.setAttribute(\"action\", \"/checkout/init\"); formtag.setAttribute(\"class\", \"buyform\"); formtag.setAttribute(\"method\", \"post\"); formtag.appendChild(hiddenDomain); formtag.appendChild(hiddenOtracker); formtag.appendChild(hiddenEids); document.body.appendChild(formtag); formtag.submit(); clearInterval(time); console.log(\"Script Activated\"); } else { console.log('button not found'); location.reload(); }"); }onPageFinished(paramWebView, paramString); if (paramString.toLowerCase().contains("/checkout/init")) { wv.loadUrl("javascript:setInterval(function() { if ((document.getElementsByClassName('_2AkmmA _7UHT_c').length > 0)) { document.getElementsByClassName('_2AkmmA _7UHT_c')[0].click() } if (document.getElementsByClassName('_3pZBmm _3C6tOa _1syowc').length == 0) { if (document.getElementsByClassName('_3uUUD5').length > 0) { document.getElementsByClassName('_3uUUD5')[0].click() } } }, 100)"); } } } } if之类的结构中的代码元素。

确切的定义取决于您的语言的语法树,即formally defined

答案 2 :(得分:0)

所有程序都包含太多块。 块只是一个概念,你不能看作功能。 块是代码的结构,用于将代码的一部分与代码的另一部分分开。 函数是块。,类是块,内部由许多块组成。