I tried using "Streamlit" which can do the Web only with Python

Introduction

This article is JSL (Japan System Giken) Advent Calendar 2020 --Qiita 20th day article.

It is an annual anniversary commemoration. : tada: Even at this age, I'm still wondering.

I haven't been working on development for a long time, so I was worried about what to write. The other day, I will talk about using Streamlit, which nikkie introduced at the" Everyone's Python Study Group "that I participated in, because it looks interesting.

What is Streamlit

Streamlit is a library and service that allows you to write a front end (Web) with Python code.

This goal

• While doing the official tutorial of Streamlit, Connpass API I would like to use it to display the latest event data.

Various versions

• Python:3.8.0
• Streamlit:3.9.2
• Pandas:1.1.5

Installation

$ pip install streamlit

Play around with the tutorial

Hello App

$ streamlit hello

Will create a project. The browser will start and you can build the following demo site.

Creating a streamlit project

Follow the tutorial and import streamlit and various libraries as follows

streamlit run [filename] will start the browser.

import streamlit as st

import numpy as np
import pandas as pd

Make sure it is reflected interactively

Just pass the title and the Pandas DataFrame like this and the browser will be updated interactively! ..

st.title('My first app')

st.write("Here's our first attempt at using data to create a table:")
st.write(pd.DataFrame({
    'first column': [1, 2, 3, 4],
    'second column': [10, 20, 30, 40]
}))

Magic command

In addition to the write function, there is a function called Magic commands, and it seems that the behavior is the same as the write function just by writing a variable as shown below.

df = pd.DataFrame({
  'first column': [1, 2, 3, 4],
  'second column': [110, 200, 300, 400]
})

df

x=10

x

Like this, it will be generated with Gorigori ** Python only **!

Data acquisition from Connpass API

It seems that you can do various things just by playing with the tutorial, so I got the data of "GEEKLAB.NAGANO" operated by our company from "Connpass API" and displayed the event information.

geeklab_eventlist.py

import streamlit as st

import pandas as pd
import requests, io
from datetime import datetime, date, timedelta
from dateutil.relativedelta import relativedelta
from PIL import Image

st.title('Geek Lab Event List')

image_url = 'https://connpass-tokyo.s3.amazonaws.com/thumbs/72/9d/729d521ab794e98b4427e9040e8f2fe9.png'
image = Image.open(io.BytesIO(requests.get(image_url).content))
st.image(image, use_column_width=True)

today = datetime.today()
startdate = datetime.strftime(today, '%Y%m')
enddate = "201402"

target_date_set = ['All cases'] 
target_date_set.append(startdate)

while startdate > enddate:
  dt = datetime.strptime(startdate, '%Y%m') - relativedelta(months=1)
  startdate = dt.strftime("%Y%m")
  target_date_set.append(startdate)

yyyymm = st.selectbox(
    'Event date',
    target_date_set
     )

count = st.slider('Number of acquisitions', 0, 100, 10)
keyword = st.text_input('keyword', '')

r = requests.get(f'https://connpass.com/api/v1/event/?series_id=2591&count={count}&ym={yyyymm}&keyword={keyword}')

titles = []
event_date_set = []
participants = []
owners_name = []

for e in r.json()["events"]:
  titles.append(e["title"])

  dt = datetime.fromisoformat(e["started_at"])
  event_date_set.append(datetime.strftime(dt, '%Y/%m/%d'))
  participants.append(e["accepted"])
  owners_name.append(e["owner_display_name"])

df = pd.DataFrame({
  'title': titles,
  'event date': event_date_set,
  'Number of participants': participants,
  'Administrator':  owners_name
})
df.style.set_properties(**{'text-align': 'center'})

df

With just this much Python code, it's amazing what you can do so far! !!

Limitations

Here is a summary of the restrictions I noticed while trying.

• The same widget cannot be defined per file
• Example) Define two selectbox

Deploy

You can deploy it by linking the GitHub repository including requirements.txt to https://share.streamlit.io/. It seems that you will be notified of invitation emails on a weekly basis, and it will take some time before it becomes available.

When you receive the invitation email, just enter the necessary information and like this Will deploy to.

at the end

After attending the study session after a long time, I tried to touch Streamlit, but when I tried using it, I came across a library that seems to be " fun ", " amazing !! ". Although there are some restrictions, I thought it was a good mechanism to quickly see if the data was visible.

Above all, it is good to be able to write in ** Python only **.

It's hard to keep catching up individually, so I reaffirmed the importance of attending study sessions on a regular basis! !! .. I would like to take this opportunity to thank nikkie! !!