Flask を使ってみたので、メモです。
Installing 1
Installing
Install and update using pip:
pip install -U FlaskGitHub - pallets/flask: The Python micro framework for building web applications.
この通りにインストールしました。
$ pip install -U Flask
Collecting Flask
Downloading https://files.pythonhosted.org/packages/9b/93/628509b8d5dc749656a9641f4caf13540e2cdec85276964ff8f43bbb1d3b/Flask-1.1.1-py2.py3-none-any.whl (94kB)
100% |████████████████████████████████| 102kB 691kB/s
Collecting Werkzeug>=0.15 (from Flask)
Downloading https://files.pythonhosted.org/packages/d1/ab/d3bed6b92042622d24decc7aadc8877badf18aeca1571045840ad4956d3f/Werkzeug-0.15.5-py2.py3-none-any.whl (328kB)
100% |████████████████████████████████| 337kB 1.3MB/s
Collecting itsdangerous>=0.24 (from Flask)
Downloading https://files.pythonhosted.org/packages/76/ae/44b03b253d6fade317f32c24d100b3b35c2239807046a4c953c7b89fa49e/itsdangerous-1.1.0-py2.py3-none-any.whl
Requirement already satisfied, skipping upgrade: click>=5.1 in /usr/lib/python3/dist-packages (from Flask) (6.7)
Collecting Jinja2>=2.10.1 (from Flask)
Downloading https://files.pythonhosted.org/packages/1d/e7/fd8b501e7a6dfe492a433deb7b9d833d39ca74916fa8bc63dd1a4947a671/Jinja2-2.10.1-py2.py3-none-any.whl (124kB)
100% |████████████████████████████████| 133kB 1.9MB/s
Requirement already satisfied, skipping upgrade: MarkupSafe>=0.23 in /usr/lib/python3/dist-packages (from Jinja2>=2.10.1->Flask) (1.0)
Installing collected packages: Werkzeug, itsdangerous, Jinja2, Flask
Could not install packages due to an EnvironmentError: [Errno 13] Permission denied: '/usr/local/lib/python3.6/dist-packages/Werkzeug-0.15.5.dist-info'
Consider using the `--user` option or check the permissions.
You are using pip version 18.1, however version 19.2.2 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
エラーになりました。
そういえば、普段 --user オプションをつけていました。
Installing 2
改めて --user オプションをつけてインストールしました。
$ pip install -U Flask --user
Collecting Flask
Using cached https://files.pythonhosted.org/packages/9b/93/628509b8d5dc749656a9641f4caf13540e2cdec85276964ff8f43bbb1d3b/Flask-1.1.1-py2.py3-none-any.whl
Collecting itsdangerous>=0.24 (from Flask)
Using cached https://files.pythonhosted.org/packages/76/ae/44b03b253d6fade317f32c24d100b3b35c2239807046a4c953c7b89fa49e/itsdangerous-1.1.0-py2.py3-none-any.whl
Requirement already satisfied, skipping upgrade: click>=5.1 in /usr/lib/python3/dist-packages (from Flask) (6.7)
Collecting Jinja2>=2.10.1 (from Flask)
Using cached https://files.pythonhosted.org/packages/1d/e7/fd8b501e7a6dfe492a433deb7b9d833d39ca74916fa8bc63dd1a4947a671/Jinja2-2.10.1-py2.py3-none-any.whl
Collecting Werkzeug>=0.15 (from Flask)
Using cached https://files.pythonhosted.org/packages/d1/ab/d3bed6b92042622d24decc7aadc8877badf18aeca1571045840ad4956d3f/Werkzeug-0.15.5-py2.py3-none-any.whl
Requirement already satisfied, skipping upgrade: MarkupSafe>=0.23 in /usr/lib/python3/dist-packages (from Jinja2>=2.10.1->Flask) (1.0)
Installing collected packages: itsdangerous, Jinja2, Werkzeug, Flask
Successfully installed Flask-1.1.1 Jinja2-2.10.1 Werkzeug-0.15.5 itsdangerous-1.1.0
You are using pip version 18.1, however version 19.2.2 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
インストールできました。
A Simple Example
次のようなサンプルのファイルを作りました。
# hello.py
from flask import Flask
app = Flask(__name__)
@app.route("/")
def hello():
return "Hello, World!"
次のように実行しました。 FLASK_APP を設定するみたいです。
$ env FLASK_APP=hello.py flask run
* Serving Flask app "hello.py"
* Environment: production
WARNING: This is a development server. Do not use it in a production deployment.
Use a production WSGI server instead.
* Debug mode: off
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
Example 2
株式のヒストリカルデータをダウンロードするサンプルを作りました。
pip で numpy, pandas, requests をインストールしてあります。
# historical-prices.py
import datetime
import io
import numpy as np
import pandas as pd
import os
import requests
from flask import Flask, request, send_from_directory
app = Flask(__name__)
@app.route("/")
def root():
title = 'Historical Prices'
res = f'''
<!DOCTYPE html>
<html>
<head>
<title>{title}</title>
<meta charset="utf-8" />
</head>
<body>
<h1>{title}</h1>
<ul>
<li><a href="/download?symbol=DJIA">Dow Jones Industrial Average (DJIA)</a></li>
<li><a href="/download?symbol=SPX">S&P 500 Index (SPX)</a></li>
<li><a href="/download?symbol=COMP">NASDAQ Composite Index (COMP)</a></li>
<li><a href="/download?symbol=NIK">NIKKEI 225 Index (NIK)</a></li>
<li><a href="/download?symbol=180460">TOPIX Index (180460)</a></li>
<li><a href="/download?symbol=SHCOMP">Shanghai Composite Index (SHCOMP)</a></li>
<li><a href="/download?symbol=HSI">Hang Seng Index (HSI)</a></li>
<li><a href="/download?symbol=UKX">FTSE 100 Index (UKX)</a></li>
<li><a href="/download?symbol=DAX">DAX (DAX)</a></li>
</ul>
</body>
</html>
'''
return res
@app.route("/download")
def download():
symbol = request.args.get('symbol')
text = get(symbol)
df = to_csv(symbol, text)
res = send_from_directory(os.getcwd(), f'{symbol}.csv', as_attachment=True, attachment_filename=f'{symbol}.csv')
os.remove(f'{symbol}.csv')
return res
def get(symbol):
url_dict = {
'DJIA': 'https://quotes.wsj.com/index/DJIA/historical-prices/download',
'SPX': 'https://quotes.wsj.com/index/SPX/historical-prices/download',
'COMP': 'https://quotes.wsj.com/index/COMP/historical-prices/download',
'NIK': 'https://quotes.wsj.com/index/JP/XTKS/NIK/historical-prices/download',
'180460': 'https://quotes.wsj.com/index/JP/TOKYO EXCHANGE (TOPIX)/180460/historical-prices/download',
'SHCOMP': 'https://quotes.wsj.com/index/CN/XSHG/SHCOMP/historical-prices/download',
'HSI': 'https://quotes.wsj.com/index/HK/XHKG/HSI/historical-prices/download',
'UKX': 'https://quotes.wsj.com/index/UK/FTSE%20UK/UKX/historical-prices/download',
'DAX': 'https://quotes.wsj.com/index/DX/XETR/DAX/historical-prices/download',
}
start_dict = {
'DJIA': datetime.date(1970, 12, 31),
'SPX': datetime.date(1978, 1, 3),
'COMP': datetime.date(1971, 2, 5),
'NIK': datetime.date(1949, 5, 16),
'180460': datetime.date(2008, 12, 30),
'SHCOMP': datetime.date(1992, 5, 8),
'HSI': datetime.date(1985, 1, 2),
'UKX': datetime.date(1985, 12, 31),
'DAX': datetime.date(1987, 12, 30),
}
url = url_dict[symbol]
start = start_dict[symbol]
end = datetime.date.today()
days = (end - start).days
payload = {
'MOD_VIEW': 'page',
'num_rows': days,
'range_days': days,
'startDate': start.strftime("%m/%d/%Y"),
'endDate': end.strftime("%m/%d/%Y"),
}
headers = {
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Firefox/68.0',
'Accept': 'text/html, */*; q=0.01',
'Accept-Language': 'ja,en-US;q=0.7,en;q=0.3',
'Referer': url.replace('/download', ''),
'Connection': 'keep-alive',
'TE': 'Trailers',
}
r = requests.get(url, params=payload, headers=headers, timeout=60)
r.raise_for_status()
r.text
return r.text
def to_csv(symbol, text):
df = pd.read_csv(io.StringIO(text), index_col=0, parse_dates=True)
df2 = df.sort_index()
df2.to_csv(f'{symbol}.csv')
return df2
これを次のように実行しました。
$ env FLASK_APP=historical-prices.py flask run
* Serving Flask app "historical-prices.py"
* Environment: production
WARNING: This is a development server. Do not use it in a production deployment.
Use a production WSGI server instead.
* Debug mode: off
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
http://127.0.0.1:5000/ にアクセスすると。
ちゃんとダウンロードできたみたいでした。
終わり
Flask は Node.js の Express のような印象を受けました。