电脑/python/Flask/jinja2模板系统.html

<!DOCTYPE html>
<html>
<head>
<!-- 2016-07-30 六 23:06 -->
<meta  charset="utf-8">
<meta  name="viewport" content="width=device-width, initial-scale=1">
<title>jinja2模块系统</title>
<meta  name="generator" content="Org-mode">
<meta  name="author" content="万泽(德山书生)">
<meta  name="description" content="制作者邮箱：a358003542@gmail.com"
>
<style type="text/css">
body {
    margin-right: auto;
    margin-left: auto;
}

.title {
    display: block;
    text-align: center;
    padding: 10px;
}

.center-block {
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}

.underline{
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}
   html, body {
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#content {
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code {
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pre {
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blockquote {
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li{
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p{
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/* dl */
dl {
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    margin-bottom: 20px;
}
dt {
    font-weight: 700;
    line-height: 150%;
    margin-top: 0.5em;
    margin-bottom: 0.5em;
}
dd {
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}

@media (min-width: 768px) {
  dt {
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}

video{
    max-width: 100%;
    margin-left: auto;
    margin-right: auto;
}

figure p{
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img{
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}

embed{
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figure{
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/*  class  */
.FRAMED{
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.NOTECARD{
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/*
table
*/
table {
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    border: 1px solid #ccc;
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table tr {
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table th,table td{
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table tr:nth-child(even) {
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ul,ol,dl{
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li{
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dd{
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#content .section ul,#content .toctree-wrapper ul,article ul{
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dl dt{
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dl dd{
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    a,a:visited{
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    thead{
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    tr,img{
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    img{
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    @page{
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    p,h2,h3{
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        widows:3}

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    #content{
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@media print{
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    @page{
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        margin: 25mm 25mm 25mm 25mm;}

    body {
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}

@media screen and (max-width: 768px){
}

@media only screen and (max-width: 480px){
}

@media screen and (max-width: 768px){
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}

@media screen and (max-width: 480px){
    .mobile-hide{
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}

@media screen and (max-width: 480px){
}

@media screen and (max-width: 768px){
    #content{
        margin-left:0;
        padding: 1em 1em;}

    #content #content{
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    #content.shift{
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        left:85%;
        top:0;
        height:100%;
        overflow:hidden}
}

@media screen and (min-width: 1400px){
    #content{
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    #content{
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}

@media screen and (max-width: 768px){
    #copyright{
        width:85%;
        display:none}

    #copyright.shift{
        display:block}

    img{
        width:100%;
        height:auto}
}

@media screen and (max-width: 480px){
    #content .sidebar{
        width:100%}
}


.figure p{
    color:#000;
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    padding:1em 0;
}

.rotate-90{
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    -moz-transform:rotate(90deg);
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.rotate-270{
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#toggle-sidebar,
#table-of-contents .close-sidebar {
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}

@media screen and (max-width: 768px) {
    #table-of-contents {
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    #table-of-contents h2 a {
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        font-size: 100%;
        line-height: 50px;
        margin: 0;
        padding: 0;
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    #table-of-contents .close-sidebar {
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       display: inline-block;
       margin: 0px 10px 0px 45px;
       padding: 10px;
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}

*{
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}

figcaption,figure,footer,header,hgroup,nav{
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ins{
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mark{
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    font-weight:bold}

small{
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sub,sup{
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sup{
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sub{
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img{
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    vertical-align:middle;
    max-width:100%}

svg:not(:root){
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figure{
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label{
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legend{
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    margin-left:-7px;
    padding:0;
    white-space:normal}

#content .danger,#content .error{
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legend{
    display:block;
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    border:0;
    padding:0;
    white-space:normal;
    margin-bottom:24px;
    font-size:150%;
    *margin-left:-7px}

label{
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    margin:0 0 0.3125em 0;
    color:#333;
    font-size:90%}

a{
    color:#2980B9;
    text-decoration:none;
    cursor:pointer}


a:hover,a:active{
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}

a:hover{
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a:visited{
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.left{
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.center{
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.right{
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hr{
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    height:1px;
    border:0;
    border-top:1px solid #e1e4e5;
    margin:24px 0;
    padding:0}

#table-of-contents li{
    list-style:none;
    margin-left: 0px;
}

#table-of-contents header{
    height:32px;
    display:inline-block;
    line-height:32px;
    padding:0 1.618em;
    display:block;
    font-weight:bold;
    text-transform:uppercase;
    font-size:80%;
    color:#2980B9;
    white-space:nowrap}

#table-of-contents ul{
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#table-of-contents li.divide-top{
    border-top:solid 1px #404040}

#table-of-contents li.divide-bottom{
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#table-of-contents li.current{
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#table-of-contents li.current a{
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    padding:0.4045em 2.427em}

#table-of-contents li.current a:hover{
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#table-of-contents li a{
    /* color:#404040; */
    padding:0.4045em 1.618em;
    position:relative;
    /* background:#fcfcfc; */
    border:none;
    /* border-bottom:solid 1px #c9c9c9; */
    /* border-top:solid 1px #c9c9c9; */
    padding-left:1.618em -4px}

#table-of-contents li.on a:hover,#table-of-contents li.current>a:hover{
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#table-of-contents li ul li a{
    /* background:#c9c9c9; */
    padding:0.4045em 2.427em}

#table-of-contents li ul li ul li a{
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#table-of-contents li.current ul{
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/* #table-of-contents li ul{ */
/*     margin-bottom:0; */
/*     display:none} */

#table-of-contents .local-toc li ul{
    display:block}

#table-of-contents li ul li a{
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    color:#b3b3b3;
    font-weight:normal}

#table-of-contents a{
    display:inline-block;
    line-height:18px;
    padding:0.4045em 1.618em;
    display:block;
    position:relative;
    font-size:90%;
    color:#b3b3b3;
    direction: ltr;
}

#table-of-contents a:hover{
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    cursor:pointer}

/* #text-table-of-contents { */
/*     overflow:scroll; */
/* } */

#table-of-contents{
    position:fixed;
    top:0;
    left:0;
    width:300px;
    overflow-x:hidden;
    overflow-y:scroll;
    height:100%;
    background:#343131;
    z-index:200;
    scrollbar-base-color: #1F1D1D;
    scrollbar-arrow-color: #b3b3b3;
    scrollbar-shadow-color: #1F1D1D;
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}

#table-of-contents h2{
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    padding:0.809em;
    display:block;
    color:#fcfcfc;
    font-size: 100%;
    margin-bottom:0.809em}

ul.nav li ul li {
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}

ul.nav li ul li ul li {
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}

ul.nav li.active ul li {
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}

ul.nav li.active ul li ul li {
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}

ul.nav li.active ul li a {
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    color: #8099B0;
    border-right:solid 1px #c9c9c9 !important;
}

ul.nav li.active ul li.active a {
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    color: black !important;
    font-weight: bold !important;
}

ul.nav li.active ul li.active ul li.active a {
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    font-weight: bold !important;
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}

ul.nav li.active ul li.active ul li a {
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    font-weight: normal !important;
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}

ul.nav li.active ul li ul li a {
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}


ul.nav li ul li ul li ul li {
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    /* display: none; /* as long as nav is on multiple levels of ul *\/ */
}

ul.nav li.active > a {
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    border-right:solid 1px #c9c9c9 !important;
}

ul.nav li.active a {
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    font-weight:bold;
    background-color: white;
    border-right:solid 0px white !important;
}

ul.nav > li.active > a {
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}

footer{
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footer p{
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#copyright, #postamble{
    position:fixed;
    bottom:0;
    left:0;
    width:300px;
    color:#fcfcfc;
    background:#1f1d1d;
    border-top:solid 10px #343131;
    font-family:"Lato","proxima-nova","Helvetica Neue",Arial,sans-serif;
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    z-index:400;
    padding:12px;
}

#postamble .author {
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}

#postamble .date {
    font-size: 90%;
    margin-bottom: 0px;
    color: #27AE60;
}

#postamble .creator,#postamble .validation {
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}

#copyright a{
    color:#2980B9;
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#copyright .rst-current-version{
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    display:block;
    text-align:right;
    font-size:90%;
    cursor:pointer;
    color:#27AE60;
    *zoom:1}

#content img{
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    height:auto !important}

#content div.figure{
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#content div.figure.align-center{
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#content .section>img,#content .section>a>img{
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.verse{
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    background-color: #E7F2FA;
    padding: 6px 20px;
    font-style:italic;
}

#content .note .last,#content .attention .last,#content .caution .last,#content .danger .last,#content .error .last,#content .hint .last,#content .important .last,#content .tip .last,#content .warning .last,#content .seealso .last,#content .admonitiontodo .last{
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#content .admonition-title:before{
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#content .section ol p,#content .section ul p{
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#content h1 .headerlink,#content h2 .headerlink,#content h3 .headerlink,#content h4 .headerlink,#content h5 .headerlink,#content h6 .headerlink,#content dl dt .headerlink{
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#content h1 .headerlink:after,#content h2 .headerlink:after,#content h3 .headerlink:after,#content h4 .headerlink:after,#content h5 .headerlink:after,#content h6 .headerlink:after,#content dl dt .headerlink:after{
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    content:"";
    font-family:FontAwesome;
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#content h1:hover .headerlink,#content h2:hover .headerlink,#content h3:hover .headerlink,#content h4:hover .headerlink,#content h5:hover .headerlink,#content h6:hover .headerlink,#content dl dt:hover .headerlink{
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#content .sidebar{
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    width:40%;
    display:block;
    margin:0 0 24px 24px;
    padding:24px;
    background:#f3f6f6;
    border:solid 1px #e1e4e5}

#content .sidebar p,#content .sidebar ul,#content .sidebar dl{
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#content .sidebar .last{
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#content .sidebar .sidebar-title{
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    font-weight:bold;
    background:#e1e4e5;
    padding:6px 12px;
    margin:-24px;
    margin-bottom:24px;
    font-size:100%}

#content .footnote-reference,#content .citation-reference{
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    font-size:90%}

span[id*='MathJax-Span']{
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.math{
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#footnotes{
    border-top:1px solid #e1e4e5;
    padding-top: 36px;
}

h2.footnotes{
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}


.footnum:before, .footref:before{
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}

.footnum:after, .footref:after{
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}

.footpara {
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    font-size: 90%;
    font-family:"Lato","proxima-nova","Helvetica Neue",Arial,sans-serif;
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    padding-left: 16px;
    padding-right: 16px;
    padding-top: 8px;
    line-height: 1.25em;
    /* display: inline; */
}
.highlight .hll { background-color: #ffffcc }
.highlight  { background: #f8f8f8; }
.highlight .c { color: #8f5902; font-style: italic } /* Comment */
.highlight .err { color: #a40000; border: 1px solid #ef2929 } /* Error */
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.highlight .k { color: #204a87; font-weight: bold } /* Keyword */
.highlight .l { color: #000000 } /* Literal */
.highlight .n { color: #000000 } /* Name */
.highlight .o { color: #ce5c00; font-weight: bold } /* Operator */
.highlight .x { color: #000000 } /* Other */
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.highlight .cs { color: #8f5902; font-style: italic } /* Comment.Special */
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.highlight .gi { color: #00A000 } /* Generic.Inserted */
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.highlight .gp { color: #8f5902 } /* Generic.Prompt */
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.highlight .kn { color: #204a87; font-weight: bold } /* Keyword.Namespace */
.highlight .kp { color: #204a87; font-weight: bold } /* Keyword.Pseudo */
.highlight .kr { color: #204a87; font-weight: bold } /* Keyword.Reserved */
.highlight .kt { color: #204a87; font-weight: bold } /* Keyword.Type */
.highlight .ld { color: #000000 } /* Literal.Date */
.highlight .m { color: #0000cf; font-weight: bold } /* Literal.Number */
.highlight .s { color: #4e9a06 } /* Literal.String */
.highlight .na { color: #c4a000 } /* Name.Attribute */
.highlight .nb { color: #204a87 } /* Name.Builtin */
.highlight .nc { color: #000000 } /* Name.Class */
.highlight .no { color: #000000 } /* Name.Constant */
.highlight .nd { color: #5c35cc; font-weight: bold } /* Name.Decorator */
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.highlight .ne { color: #cc0000; font-weight: bold } /* Name.Exception */
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.highlight .nl { color: #f57900 } /* Name.Label */
.highlight .nn { color: #000000 } /* Name.Namespace */
.highlight .nx { color: #000000 } /* Name.Other */
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.highlight .ow { color: #204a87; font-weight: bold } /* Operator.Word */
.highlight .w { color: #f8f8f8; text-decoration: underline } /* Text.Whitespace */
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<div id="content">
<header>
<h1 class="title">jinja2模块系统</h1>
</header><nav id="table-of-contents">
<h2>Table of Contents</h2>
<div id="text-table-of-contents">
<ul>
<li><a href="#orgheadline1">1. 前言</a></li>
<li><a href="#orgheadline2">2. 注释</a></li>
<li><a href="#orgheadline3">3. 变量</a></li>
<li><a href="#orgheadline4">4. for语句</a></li>
<li><a href="#orgheadline6">5. 条件分支</a>
<ul>
<li><a href="#orgheadline5">5.1. tests</a></li>
</ul>
</li>
<li><a href="#orgheadline7">6. html特殊符号问题</a></li>
<li><a href="#orgheadline8">7. 模板文件继承机制</a></li>
<li><a href="#orgheadline9">8. jinja2提供的一些全局函数</a></li>
<li><a href="#orgheadline10">9. filters</a></li>
<li><a href="#orgheadline11">10. 国际化</a></li>
<li><a href="#orgheadline13">11. jinja2模板系统</a>
<ul>
<li><a href="#orgheadline12">11.1. 加入错误页面</a></li>
</ul>
</li>
</ul>
</div>
</nav>


<div class="outline-2">
<h2 id="orgheadline1">前言</h2>
<div class="outline-text-2" id="text-1">
<p>
因为我们使用jinja2模板系统主要是在flask框架里面，所以jinja2提供的api接口我们不需要太多了解了，只需要知道在flask框架中如何使用模板文件即可。本文主要讨论如何编写模板文件的细节。另外jinja2模板系统也不一定局限于html文件，只要是任何txt文本即可，所以如果读者有兴趣，利用jinja2模块系统弄出一个latex或者emacs的org生成器也是可以的。
</p>
</div>
</div>

<div class="outline-2">
<h2 id="orgheadline2">注释</h2>
<div class="outline-text-2" id="text-2">
<p>
这里面的内容是模板文件的注释内容。
</p>
<pre>
{# ... #}
</pre>
</div>
</div>


<div class="outline-2">
<h2 id="orgheadline3">变量</h2>
<div class="outline-text-2" id="text-3">
<p>
这里算是jinja2模板的主体内容了，里面的变量可以直接使用，在render的时候传进去即可。然后 <code>object.a</code> 这样的dot法引用，或者 <code>object['a']</code> 这样的利用对象 <code>__getitem__</code> 内置方法来调用值的形式也支持。
</p>
<pre>
{{ ... }}
</pre>

<p>
变量的值在jinja2模板系统中调用之后将会变成字符串然后插入在文档中，这就不多说了。
</p>
</div>
</div>


<div class="outline-2">
<h2 id="orgheadline4">for语句</h2>
<div class="outline-text-2" id="text-4">
<p>
for语句结构如下所示:
</p>
<pre>
&lt;ul&gt;
{% for user in users %}
  &lt;li&gt;{{ user.username }}&lt;/li&gt;
{% endfor %}
&lt;/ul&gt;
</pre>

<p>
此外jinja2还有一种写法，这两种写法是等价的:
</p>
<pre>
&lt;ul&gt;
# for user in users
  &lt;li&gt;{{ user.username }}&lt;/li&gt;
# endfor
&lt;/ul&gt;
</pre>
</div>
</div>

<div class="outline-2">
<h2 id="orgheadline6">条件分支</h2>
<div class="outline-text-2" id="text-5">
<p>
条件分支主要用于有条件的显示某些内容。
</p>
</div>


<div class="outline-3">
<h3 id="orgheadline5">tests</h3>
<div class="outline-text-3" id="text-5-1">
<p>
测试器
</p>
</div>
</div>
</div>


<div class="outline-2">
<h2 id="orgheadline7">html特殊符号问题</h2>
<div class="outline-text-2" id="text-6">
<p>
如果你的变量有这些html的特殊符号:
</p>
<pre>
&lt;  &gt;  &amp;  "
</pre>

<p>
假设你没有在flask中使用jinja2模板系统，那么这些字符是没有经过特殊处理的，那么比如说 <code>&lt;b&gt;test&lt;/b&gt;</code> 这段字符串到了html文档中就将以粗体的形式显示。如果你希望显示这些符号，那么可以使用 <strong>escape</strong> 过滤器来做到这点:
</p>

<pre>
{{ test|escape }}
</pre>

<p>
或者:
</p>
<pre>
{{ test|e }}
</pre>
<p>
都是一样的。
</p>

<p>
这里的过滤器有点类似bash的管道的意思，意思是将输出的字符串经过额外的操作。
</p>

<p>
但一般推荐的风格是html标签都放在jinja2模板系统的外面，jinja2模板系统只处理最核心的那些字符串。所以flask是设置为全局auto escape的，这是正确的思路。如果你确实有某些html标签就希望是html标签的形式显示出来，而不经过escape，那么可以采用 <strong>safe</strong> 过滤器<sup><a id="fnr.1" class="footref" href="#fn.1">1</a></sup> 。
</p>

<pre>
{{ "&lt;b&gt;test&lt;/b&gt;"|safe }}
</pre>
</div>
</div>


<div class="outline-2">
<h2 id="orgheadline8">模板文件继承机制</h2>
<div class="outline-text-2" id="text-7">
<p>
jinja2的模板文件有一种继承机制，可以让你基于某个模板文件来建构出另外一个模板文件，前面那个模板文件大概可以称作模板文件的模板文件吧。具体使用是在父模板（模板文件的模板文件）构建一些block区块，如下所示:
</p>
<pre>
&lt;title&gt;{% block title %} {% endblock %}&lt;/title&gt;
</pre>

<p>
这里构建了一个title区块。
</p>

<p>
然后子模板首先继承父模板所有的内容:
</p>
<pre>
{% extends "base.html" %}
</pre>

<p>
然后一些需要定制的部分，比如说这里的title部分，做成block之后，子模板文件可以重新定义这个title block:
</p>
<pre>
{% extends "base.html" %}
{% block title}books - the classic books of  which you want to collected
{% endblock %}
</pre>

<p>
此外子模块在block重载的时候，你还可以用
</p>
<pre>
{{ super() }}
</pre>
<p>
来加载父模块在该block中的一些定义。
</p>

<p>
上面title block的内容你可以如下引用之:
</p>
<pre>
{{ self.title() }}
</pre>
</div>
</div>


<div class="outline-2">
<h2 id="orgheadline9">jinja2提供的一些全局函数</h2>
</div>


<div class="outline-2">
<h2 id="orgheadline10">filters</h2>
<div class="outline-text-2" id="text-9">
<p>
过滤器就是一些额外的字符串操作函数，一般推荐还是在python代码中把要输出显示的字符串处理好吧，下面列出一些函数简单了解下即可。
</p>
</div>
</div>


<div class="outline-2">
<h2 id="orgheadline11">国际化</h2>
</div>


<div class="outline-2">
<h2 id="orgheadline13">jinja2模板系统</h2>
<div class="outline-text-2" id="text-11">
<p>
{{ x }}   x是个变量，等下将被替换为字符串。
</p>

<p>
rend_template(what,key=value)
</p>


<p>
Hello, {{ name|capitalize }} 
</p>


<p>
safe  后面再详解   
capitalize  首字母大写，其他字母小写。
lower
upper
title 每个word都capitalize
trim 前后空格去除
striptags html tags 去除
</p>


<p>
safe  比如说 &lt;h1&gt; &#x2026; 将不会被解析
</p>

<p>
分支
</p>
<pre>
{% if user %}
Hello, {{ user }}!
{% else %}
Hello, Stranger!
{% endif %}
</pre>


<p>
for语句
</p>
<pre>
&lt;ul&gt;
{% for comment in comments %}
&lt;li&gt;{{ comment }}&lt;/li&gt;
{% endfor %}
&lt;/ul&gt;
</pre>

<p>
宏 和python的函数类似，遇到即将其展开。
</p>

<pre>
{% macro render_comment(comment) %}
&lt;li&gt;{{ comment }}&lt;/li&gt;
{% endmacro %}
&lt;ul&gt;
{% for comment in comments %}
{{ render_comment(comment) }}
{% endfor %}
&lt;/ul&gt;
</pre>

<p>
外部宏文件 引入
</p>
<pre>
{% import 'macros.html' as macros %}
</pre>

<pre>
{% import 'macros.html' as macros %}
&lt;ul&gt;
{% for comment in comments %}
{{ macros.render_comment(comment) }}
{% endfor %}
&lt;/ul&gt;
</pre>


<p>
引入
</p>
<pre>
{% include 'common.html' %}
</pre>

<p>
模板的继承
base.html
</p>
<pre>
&lt;html&gt;
&lt;head&gt;
{% block head %}
&lt;title&gt;{% block title %}{% endblock %} - My Application&lt;/title&gt;
{% endblock %}
&lt;/head&gt;
&lt;body&gt;
{% block body %}
{% endblock %}
&lt;/body&gt;
&lt;/html&gt;
</pre>

<pre>
{% extends "base.html" %}
{% block title %}Index{% endblock %}
{% block head %}
{{ super() }}
&lt;style&gt;
&lt;/style&gt;
{% endblock %}
{% block body %}
&lt;h1&gt;Hello, World!&lt;/h1&gt;
{% endblock %}
</pre>

<p>
后面重定义的block就是原地插入的意思，super()来保留原来的内容。
</p>
</div>


<div class="outline-3">
<h3 id="orgheadline12">加入错误页面</h3>
<div class="outline-text-3" id="text-11-1">
<pre>
@app.errorhandler(404)
def page_not_found(e):
    return render_template('404.html'),404
</pre>
</div>
</div>
</div>
<div id="footnotes">
<h2 class="footnotes">Footnotes: </h2>
<div id="text-footnotes">

<div class="footdef"><sup><a id="fn.1" class="footnum" href="#fnr.1">1</a></sup> <div class="footpara">参考了 <a href="http://stackoverflow.com/questions/3206344/passing-html-to-template-using-flask-jinja2">这个网页</a> 。</div></div>


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