How to implement Gantt chart drawing in Python?

Preliminary preparation

Because we need to use the streamlit, streamlit-aggrid and plotly modules this time, first pass the The pip command downloads these modules, of which streamlit-aggrid is mainly used to present the data table on the page

pip install streamlit-aggrid
pip install plotly

The structure of the page

The overall page The structure is that there is a toolbar on the left, which contains some brief introductions to the web page, and a module that hopes users to rate and give feedback

. Section1 on the right is the template style of the project planning document, mainly in CSV Write clearly the details of the task in the file, including task name, task description, start and end time, etc. Section2 allows users to upload their own CSV files, modify the content of the items in the CSV file and provide a visual presentation, while Section3 exports the above content to an HTML file.

Code part

The following is the code part of the page

from st_aggrid import AgGrid
import streamlit as st
import pandas as pd
import numpy as np
import plotly.express as px
from  PIL import Image
import io

Next we will develop the part of the toolbar on the left, mainly to provide a simple introduction to the page and scoring functions

logo = Image.open(r'wechat_logo.jpg')
st.sidebar.image(logo,  width=120)

with st.sidebar.expander("关于此APP的功能"):
     st.write("""
        项目的简单介绍)
     """)

with st.sidebar.form(key='columns_in_form',clear_on_submit=True): 
    st.write('反馈')
    st.write(&#39;<style>div.row-widget.stRadio > div{flex-direction:row;} </style>&#39;, unsafe_allow_html=True) # 水平方向的按钮
    rating=st.radio("打分",(&#39;1&#39;,&#39;2&#39;,&#39;3&#39;,&#39;4&#39;,&#39;5&#39;),index=4)
    text=st.text_input(label=&#39;反馈&#39;)
    submitted = st.form_submit_button(&#39;提交&#39;)
    if submitted:
      st.write(&#39;感谢&#39;)
      st.markdown(&#39;您的评分是：&#39;)
      st.markdown(rating)
      st.markdown(&#39;您的反馈是：&#39;)
      st.markdown(text)

The results are shown in the figure below

Development of the main page-Section 1

The next step is the development of Section 1 of the main page, mainly for display The style of the project CSV file, which columns it contains, what the column names are, etc., the code is as follows

st.markdown(""" <style> .font {                                          
    font-size:30px ; font-family: &#39;Cooper Black&#39;; color: #FF9633;} 
    </style> """, unsafe_allow_html=True)
st.markdown(&#39;<p class="font">上传您的CSV文件</p>&#39;, unsafe_allow_html=True)

st.subheader(&#39;第一步：下载模板文件&#39;)
image = Image.open(r&#39;example.png&#39;) # 模板文件的截图
st.image(image,  caption=&#39;确保列名是一致的&#39;)

@st.cache_data
def convert_df(df):
     return df.to_csv().encode(&#39;utf-8&#39;)

df=pd.read_csv(r&#39;template.csv&#39;, encoding=&#39;gbk&#39;)
csv = convert_df(df)
st.download_button(
     label="下载模板",
     data=csv,
     file_name=&#39;project_template.csv&#39;,
     mime=&#39;text/csv&#39;,
 )

We provide a download button that allows users to download the template file with one click, and the final appearance is like this

Development of home page -Section 2

The next step is to upload our own CSV file, here we use the streamlit_aggrid module , the advantage of this module is that it can display the data table and modify the data in it,

st.subheader('Step 2: Upload your project plan file')
uploaded_file = st.file_uploader(
    "上传文件",
    type=['csv'])
if uploaded_file is not None:
    Tasks = pd.read_csv(uploaded_file, encoding='gbk')
    Tasks['Start'] = Tasks['Start'].astype('datetime64')
    Tasks['Finish'] = Tasks['Finish'].astype('datetime64')

    grid_response = AgGrid(
        Tasks,
        editable=True,
        height=300,
        width='100%',
    )

    updated = grid_response['data']
    df = pd.DataFrame(updated)

output

Next It is a visual presentation of data. Here we use the Plotly module to draw a Gantt chart. We can choose to draw it based on the team's dimension or the progress of the project completion. The code is as follows

st.subheader('第三部：绘制甘特图')

Options = st.selectbox("以下面哪种维度来绘制甘特图:", ['Team', 'Completion Pct'], index=0)
if st.button('绘制甘特图'):
    fig = px.timeline(
        df,
        x_start="Start",
        x_end="Finish",
        y="Task",
        color=Options,
        hover_name="Task Description"
    )

    fig.update_yaxes(
        autorange="reversed")

    fig.update_layout(
        title='Project Plan Gantt Chart',
        bargap=0.2,
        height=600,
        xaxis_title="Date",
        yaxis_title="Project Name",
        title_x=0.5,
        xaxis=dict(
            tickfont_size=15,
            tickangle=270,
            rangeslider_visible=True,
            side="top",
            showgrid=True,
            zeroline=True,
            showline=True,
            showticklabels=True,
            tickformat="%x\n",
        )
    )

    fig.update_xaxes(tickangle=0, tickfont=dict(family='Rockwell', color='blue', size=15))
    st.plotly_chart(fig, use_container_width=True)  # 绘制甘特图至页面上
    st.subheader(
        'Bonus: 导出至HTML') 
    buffer = io.StringIO()
    fig.write_html(buffer, include_plotlyjs='cdn')
    html_bytes = buffer.getvalue().encode()
    st.download_button(
        label='Export to HTML',
        data=html_bytes,
        file_name='Gantt.html',
        mime='text/html'
    )
else:
    st.write('---')

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