Nov 7, 2020

How to install pyenv, pipenv

1. make sure the following was installed sudo apt-get install -y build-essential libssl-dev zlib1g-dev libbz2-dev \ libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev libncursesw5-dev \ xz-utils tk-dev libffi-dev liblzma-dev python3-openssl git 2. Install pyenv sudo apt install pyenv or curl https://pyenv.run | bash or curl -L https://github.com/pyenv/pyenv-installer/raw/master/bin/pyenv-installer | bash

Pipenv

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Pipenv

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How to install pyenv, pipenv

1. make sure the following was installed

sudo apt-get install -y build-essential libssl-dev zlib1g-dev libbz2-dev \
libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev libncursesw5-dev \
xz-utils tk-dev libffi-dev liblzma-dev python3-openssl git

2. Install pyenv

sudo apt install pyenv
or
curl https://pyenv.run | bash
or
curl -L https://github.com/pyenv/pyenv-installer/raw/master/bin/pyenv-installer | bash

3. pyenv commands:

pyenv versionspyenv install -v 3.7.9pyenv global 3.7.9

4. pipenv

pipenv --python 3.7.9pipenv install <package>pipenv shell
python --version

5. update setuptools in pipenv. without this, wsl environment often raise error.

pip install -U setuptools

Sep 22, 2020

Python convert time string timezone

localFormat = “%Y-%m-%dT%H:%M:%S.000000000Z” # first specify string format localFormat = “%Y-%m-%dT%H:%M:%S.000000000Z” # construct a datetime from string localmoment_naive = datetime.strptime('2020-09-22T01:02:03.000000000Z', localFormat) # set timezone to utc utcomment = localmoment_naive.replace(tzinfo=pytz.utc) # convert time to expected timezone localDatetime = utcomment.astimezone(pytz.timezone("America/Toronto"))

Timezone

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Timezone

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Jul 12, 2020

DataFrame resample ohlc from daily to weekly

import pandas_datareader as pdr # Load the Data datadf = pdr.DataReader(“MSFT”, start=’2019–1–1', end=’2020–12–31', data_source=’yahoo’)[[‘Open’, ‘High’, ‘Low’, ‘Close’, ‘Volume’]] data = bt.feeds.PandasData(dataname=datadf) cerebro.adddata(data) # First add the original data — smaller timeframe # this is key function to resample data to weekly datadf1 = datadf.resample(‘W’, label=’left’).agg({ ‘Open’: ‘first’, ‘High’: ‘max’, ‘Low’: ‘min’, ‘Close’: ‘last’, ‘Volume’: ‘sum’ })

Dataframes

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Dataframes

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DataFrame resample ohlc from daily to weekly

import pandas_datareader as pdr# Load the Data
 datadf = pdr.DataReader(“MSFT”,
 start=’2019–1–1',
 end=’2020–12–31',
 data_source=’yahoo’)[[‘Open’, ‘High’, ‘Low’, ‘Close’, ‘Volume’]]data = bt.feeds.PandasData(dataname=datadf)
 cerebro.adddata(data) # First add the original data — smaller timeframe# this is key function to resample data to weekly
 datadf1 = datadf.resample(‘W’, label=’left’).agg({
 ‘Open’: ‘first’,
 ‘High’: ‘max’,
 ‘Low’: ‘min’,
 ‘Close’: ‘last’,
 ‘Volume’: ‘sum’
 })datadf1.reset_index(level=0, inplace=True)
 # have to add 1 day to each ‘Date’, tried many ways, only this works.
 datadf1[‘Date’] = pd.to_datetime(datadf1[‘Date’]).apply(pd.DateOffset(1))
 datadf1 = datadf1.set_index(‘Date’)
 # end of resample to weekly

Jun 25, 2020

Linux in VirtualBox network problem with host vpn

C:\...\VirtualBox\VBoxManage modifyvm "VM name" --natdnshostresolver1 on

Virtualbox

1 min read

Virtualbox

1 min read

Apr 28, 2020

timstamptz in postgresql

foo=> SET TIMEZONE TO 'Japan'; SET foo=> SELECT '2011-01-01 00:00:00'::TIMESTAMP; timestamp --------------------- 2011-01-01 00:00:00 (1 row) foo=> SELECT '2011-01-01 00:00:00'::TIMESTAMP WITH TIME ZONE; timestamptz ------------------------ 2011-01-01 00:00:00+09 (1 row) foo=> SELECT '2011-01-01 00:00:00+03'::TIMESTAMP; timestamp --------------------- 2011-01-01 00:00:00 (1 row) foo=> SELECT '2011-01-01 00:00:00+03'::TIMESTAMP WITH TIME ZONE; timestamptz ------------------------ 2011-01-01 06:00:00+09 (1 row) foo=> SET TIMEZONE TO 'Australia/Melbourne'; SET foo=> SELECT '2011-01-01 00:00:00'::TIMESTAMP; timestamp --------------------- 2011-01-01 00:00:00 (1 row) foo=> SELECT '2011-01-01 00:00:00'::TIMESTAMP WITH TIME ZONE; timestamptz ------------------------ 2011-01-01 00:00:00+11 (1 row) foo=> SELECT '2011-01-01 00:00:00+03'::TIMESTAMP; timestamp --------------------- 2011-01-01 00:00:00 (1 row) foo=> SELECT '2011-01-01 00:00:00+03'::TIMESTAMP WITH TIME ZONE; timestamptz ------------------------ 2011-01-01 08:00:00+11 (1 row)

Postgresql

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Postgresql

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Apr 23, 2020

Python convert rfc3339 time to timezone time

import iso8601 import pytz _date_obj=iso8601.parse_date("2018-09-07T04:57:58.050-07:00") _date_utc=_date_obj.astimezone(pytz.timezone('America/Toronto')) _date_utc_zformat=_date_utc.strftime('%Y-%m-%dT%H:%M:%SZ') print(_date_utc_zformat)

Timezone

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Timezone

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Apr 13, 2020

Set JDBC ResultSet Default TimeZone

Write this before your connection attempt: TimeZone timeZone = TimeZone.getTimeZone("yourTimeZone"); // e.g. "Europe/Rome" TimeZone.setDefault(timeZone);

Jdbc

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Jdbc

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Apr 12, 2020

Java code convert RFC3339 and Unix timestamps to Zoned time

RFC3339 time could be converted to any zoned time. DateTimeFormatter formatter = DateTimeFormatter .ofPattern("yyyy-MM-dd HH:mm:ss") .withZone(ZoneId.of("America/Toronto")); Instant instant = Instant.parse( "2020–04–05T21:00:00.000000000Z" ); ZoneId z = ZoneId.of( "America/Toronto" ); ZonedDateTime zdt = instant.atZone( z ); System.out.io.print(zdt.format((formatter))); 2. Unix timestamps DateTimeFormatter formatter = DateTimeFormatter .ofPattern("yyyy-MM-dd HH:mm:ss") .withZone(ZoneId.of("America/Toronto"));

Rfc 3339

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Rfc 3339

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Apr 12, 2020

Spring boot disable tomcat

In application.properties. spring.main.web-application-type=none 2. In main function. SpringApplication application = new SpringApplication(JfxQuotesServerApplication.class); application.setWebApplicationType(WebApplicationType.NONE); application.run(args);

Spring Boot

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Spring Boot

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Apr 12, 2020

TimescaleDB start

Install PostgreSql 11. $ sudo rpm -Uvh https://yum.postgresql.org/11/redhat/rhel-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm $ sudo yum install postgresql11-contrib 2. install Docker image. $ docker run -d — name timescaledb -p 5432:5432 -e POSTGRES_PASSWORD=password timescale/timescaledb:latest-pg11 3. Connect to the server. $ psql -h localhost -p 5432 -U postgres

Timescaledb

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Timescaledb

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