Streamlit Multipage

一个简单的Python包，用于使用streamlit实现多页应用。

pip install streamlit-multipage

入门指南

简单的单页应用

给定一个Python文件中的streamlit应用，如下所示

import streamlit as st

st.title("My Amazing App")
name = st.text_input("Your Name: ")
st.write(f"Hello {name}!")

将其包装在一个带有st参数和任意关键字参数的函数中。

import streamlit as st
from streamlit_multipage import MultiPage


def my_page(st, **state):
    st.title("My Amazing App")
    name = st.text_input("Your Name: ")
    st.write(f"Hello {name}!")


app = MultiPage()
app.st = st

app.add_app("Hello World", my_page)

app.run()

此示例非常简单，不会提供额外的价值。下一个示例将介绍状态持久化。

保存状态

如果状态应在重新运行（按R）或应用程序运行（运行streamlit run）之间持久化。可以通过调用save函数来保存变量，并通过state字典方便地访问它们。

import streamlit as st
from streamlit_multipage import MultiPage


def my_page(st, **state):
    st.title("My Amazing App")
    name_ = state["name"] if "name" in state else ""
    name = st.text_input("Your Name: ", value=name_)
    st.write(f"Hello {name}!")

    MultiPage.save({"name": name})


app = MultiPage()
app.st = st

app.add_app("Hello World", my_page)

app.run()

多页

处理多页时，工作流程是相同的。如果读取，始终清理输入并确保值可用且正确。

import streamlit as st
from streamlit_multipage import MultiPage


def input_page(st, **state):
    st.title("Body Mass Index")

    weight_ = state["weight"] if "weight" in state else 0.0
    weight = st.number_input("Your weight (Kg): ", value=weight_)

    height_ = state["height"] if "height" in state else 0.0
    height = st.number_input("Your height (m): ", value=height_)

    if height and weight:
        MultiPage.save({"weight": weight, "height": height})


def compute_page(st, **state):
    st.title("Body Mass Index")

    if "weight" not in state or "height" not in state:
        st.warning("Enter your data before computing. Go to the Input Page")
        return

    weight = state["weight"]
    height = state["height"]

    st.metric("BMI", round(weight / height ** 2, 2))


app = MultiPage()
app.st = st

app.add_app("Input Page", input_page)
app.add_app("BMI Result", compute_page)

app.run()

使用命名空间

在处理多页时，可能会出现变量名冲突，默认情况下，所有变量都保存在名为global的公共命名空间中，但也可以定义自定义命名空间。一页可以同时写入多个命名空间。

import streamlit as st
from streamlit_multipage import MultiPage


def input_page(st, **state):
    namespace = "input"
    variables = state[namespace] if namespace in state else {}
    st.title("Tax Deduction")

    salary_ = variables["salary"] if "salary" in variables else 0.0
    salary = st.number_input("Your salary (USD): ", value=salary_)

    tax_percent_ = variables["tax_percent"] if "tax_percent" in variables else 0.0
    tax_percent = st.number_input("Taxes (%): ", value=tax_percent_)

    total = salary * (1 - tax_percent)

    if tax_percent and salary:
        MultiPage.save({"salary": salary, "tax_percent": tax_percent}, namespaces=[namespace])

    if total:
        MultiPage.save({"total": total}, namespaces=[namespace, "result"])


def compute_page(st, **state):
    namespace = "result"
    variables = state[namespace] if namespace in state else {}
    st.title("Your Salary After Taxes")

    if "total" not in variables:
        st.warning("Enter your data before computing. Go to the Input Page")
        return

    total = variables["total"]

    st.metric("Total", round(total, 2))


app = MultiPage()
app.st = st

app.add_app("Input Page", input_page)
app.add_app("Net Salary", compute_page)

app.run()

自动命名空间

如果将命名空间设置为与App名称（add_app的第一个参数）相同，则状态在发送到函数之前将预先过滤。

import streamlit as st
from streamlit_multipage import MultiPage


def input_page(st, **state):
    st.title("Tax Deduction")

    salary_ = state["salary"] if "salary" in state else 0.0
    salary = st.number_input("Your salary (USD): ", value=salary_)

    tax_percent_ = state["tax_percent"] if "tax_percent" in state else 0.0
    tax_percent = st.number_input("Taxes (%): ", value=tax_percent_)

    total = salary * (1 - tax_percent)

    if tax_percent and salary:
        MultiPage.save({"salary": salary, "tax_percent": tax_percent}, namespaces=["Input Page"])

    if total:
        MultiPage.save({"total": total}, namespaces=["Net Salary"])


def compute_page(st, **state):
    st.title("Your Salary After Taxes")

    if "total" not in state:
        st.warning("Enter your data before computing. Go to the Input Page")
        return

    total = state["total"]

    st.metric("Total", round(total, 2))


app = MultiPage()
app.st = st

app.add_app("Input Page", input_page)
app.add_app("Net Salary", compute_page)

app.run()

目录结构

处理多个复杂页面时，将它们都放在一个.py文件中并不方便。此示例显示了如何布局目录结构以拥有一个组织良好的项目。

.
└── root/
    ├── pages/
    │   ├── __init__.py
    │   ├── input_data.py
    │   └── result.py
    └── main.py/

input_data.py

from streamlit_multipage import MultiPage


def input_page(st, **state):
    st.title("Tax Deduction")

    salary_ = state["salary"] if "salary" in state else 0.0
    salary = st.number_input("Your salary (USD): ", value=salary_)

    tax_percent_ = state["tax_percent"] if "tax_percent" in state else 0.0
    tax_percent = st.number_input("Taxes (%): ", value=tax_percent_)

    total = salary * (1 - tax_percent)

    if tax_percent and salary:
        MultiPage.save({"salary": salary, "tax_percent": tax_percent}, namespaces=["Input Page"])

    if total:
        MultiPage.save({"total": total}, namespaces=["Net Salary"])

Result.py

def compute_page(st, **state):
    st.title("Your Salary After Taxes")

    if "total" not in state:
        st.warning("Enter your data before computing. Go to the Input Page")
        return

    total = state["total"]

    st.metric("Total", round(total, 2))

__init__.py

from .input_data import input_page
from .result import compute_page

pages = {
    "Input Page": input_page,
    "Net Salary": compute_page,
}

main.py

from pages import pages

import streamlit as st
from streamlit_multipage import MultiPage


app = MultiPage()
app.st = st

for app_name, app_function in pages.items():
    app.add_app(app_name, app_function)

app.run()

着陆页

还可以显示一个仅在启动时显示并随后跳转到主应用的着陆页。着陆页仅提供信息，且无法访问状态。

import streamlit as st
from streamlit_multipage import MultiPage, save


def input_page(st, **state):
    """See Example on Multipage"""


def compute_page(st, **state):
    """See Example on Multipage"""


def landing_page(st):
    st.title("This is a Multi Page Application")
    st.write("Feel free to leave give a star in the Github Repo")


app = MultiPage()
app.st = st

app.add_app("Landing", landing_page, initial_page=True)
app.add_app("Input Page", input_page)
app.add_app("BMI Result", compute_page)

app.run()

定制

存在额外的功能来定制用户界面。在这个示例中，所有默认文本都被替换成了自定义信息。

import streamlit as st
from streamlit_multipage import MultiPage, save


def input_page(st, **state):
    """See Example on Multipage"""


def compute_page(st, **state):
    """See Example on Multipage"""


def landing_page(st):
    """See Example on Landing Page"""


def footer(st):
    st.write("Developed by [ELC](https://elc.github.io)")


def header(st):
    st.write("This app is free to use")


def sidebar(st):
    st.button("Donate (Dummy)")


app = MultiPage()
app.st = st

app.start_button = "Go to the main page"
app.navbar_name = "Other Pages:"
app.next_page_button = "Next Chapter"
app.previous_page_button = "Previous Chapter"
app.reset_button = "Delete Cache"
app.navbar_style = "SelectBox"

app.header = header
app.footer = footer
app.navbar_extra = sidebar

app.hide_menu = True
app.hide_navigation = True

app.add_app("Landing", landing_page, initial_page=True)
app.add_app("Input Page", input_page)
app.add_app("BMI Result", compute_page)

app.run()

安装

无需安装

这是一个非常简单的脚本，如果不想引入新的和小型依赖项，只需将 src 文件夹的内容复制粘贴到您的项目中（一个单独的文件）。请注意，这种方法不包括使用依赖项的所有优点，例如更新、依赖项跟踪等。

通过Pip

运行以下命令进行安装

pip install streamlit-multipage

唯一的依赖项是 streamlit，它应该已经安装。如果没有安装，它将自动安装。如果 pickle 模块无法处理保存状态中的对象，则可以选择安装 joblib。

类似的项目

许多人试图实现多页streamlit应用，因此开发了多个库来实现这个目标。以下列出了一些：

• Hydralit
• streamlit-multiapps
• streamlit-pages

如果这个项目不符合您的需求，请也查看这些。

维护者

该项目由Yan Almeida和Ezequiel Leonardo Castaño维护