for循环语法：
{% for 变量 in 可迭代对象 %}
for循环要做的任务
{% endfor %}
if语句语法：
{% if 条件 %}
条件为true
{% else %}
条件为false
{% endif %}
loop语法 for循环中使用 可以添加索引：
{{ loop.index }} 序号是从1开始
{{ loop.index0 }} 序号是从0开始
{{ loop.revindex }} 序号是倒序 最后结束是1
{{ loop.revindex0 }} 序号是倒序 最后结束是0
案例：app.py
from flask import Flask from flask import make_response, request, render_template,redirect,url_for import setting,json app = Flask(__name__) app.config.from_object(setting) @app.route('/show') def show(): girls = ["yanan","zhouqiang","nike","puma"] users = [ {"name":"zhouqiang","age":18,"gender":"man","address":"anhuihefei"}, {"name": "zhouqiang", "age": 18, "gender": "man", "address": "anhuihefei"}, {"name": "zhouqiang", "age": 18, "gender": "man", "address": "anhuihefei"}, {"name": "zhouqiang", "age": 18, "gender": "man", "address": "anhuihefei"}, {"name": "zhouqiang", "age": 18, "gender": "man", "address": "anhuihefei"}, {"name": "zhouqiang", "age": 18, "gender": "man", "address": "anhuihefei"}, {"name": "zhouqiang", "age": 18, "gender": "man", "address": "anhuihefei"} ] return render_template('test.html',users = users) # 如果没有找到匹配的，会以空白字符串填充 if __name__ == '__main__': app.run(host='127.0.0.1', port=5000)
html
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <style> .a{ color:red; } </style> </head> <body> <div>用户信息展示</div> <ul> {% for girl in girls %} {% if girl|length >=5 %} <li class="a"> {{ girl }} </li> {% else %} <li> {{ girl }} </li> {% endif %} {% endfor %} </ul> <table> {% for user in users %} <tr {% if loop.last %} style="background-color: deeppink" {% endif %}> #判断是否是最后一行，如果是就添加样式 <td>{{ loop.index }}</td> <td>{{ loop.index0 }}</td> <td>{{ user.name }}</td> <td>{{ user.age }}</td> <td>{{ user.gender }}</td> <td>{{ user.address }}</td> </tr> {% endfor %} </table> </body> </html>