datetime.md

Datetime Plots

• Introduction
• Datetime Plot
• Candlestick Plot

Main Guide

Introduction

• Plotting dates or times simply requires passing a list of date-time string objects (such as "01/01/2000", "12:30:32" or "01/01/2000 12:30:32") to the plotting functions.

• To control how plotext interprets string as date-time objects use the date_form() method, where you can change its:

  • input_form parameter to control the form of date-time strings inputted by the user,

  • output_form parameter to control the form of date-time strings outputted by plotext (by default equal to input_form), including outputted axes date-time ticks.

• The date-time string forms are the standard ones, with the % symbol removed for simplicity; eg: d/m/Y (by default), or d/m/Y H:M:S.

• If needed, most of the functions that follow allow to optionally set their input and output forms independently, with their correspondent parameters, overwriting the date_form() settings.

• To get today in datetime or string form use today_datetime() and today_string() respectively.

• To turn a datetime object into a string use datetime_to_string() or datetimes_to_strings() for a list instead.

• To turn a string into a datetime object use string_to_datetime().

• To turn a string to a numerical time-stamp use string_to_time() and strings_to_time() for a list of strings.

• The method set_time0() sets the origin of time to the string provided; this function is useful in log scale, in order to avoid hitting the 0 time-stamp.

Main Guide, Datetime Menu

Datetime Plot

To plot dates and/or times use either plt.scatter() or plt.plot() functions directly.

Here is an example, which requires the package yfinance:

import yfinance as yf
import plotext as plt

plt.date_form('d/m/Y')

start = plt.string_to_datetime('11/04/2022')
end = plt.today_datetime()
data = yf.download('goog', start, end)

prices = list(data["Close"])
dates = plt.datetimes_to_string(data.index)

plt.plot(dates, prices)

plt.title("Google Stock Price")
plt.xlabel("Date")
plt.ylabel("Stock Price $")
plt.show()

or directly on terminal:

python3 -c "import yfinance as yf; import plotext as plt; plt.date_form('d/m/Y'); start = plt.string_to_datetime('11/04/2022'); end = plt.today_datetime(); data = yf.download('goog', start, end); prices = list(data['Close']); dates = plt.datetimes_to_string(data.index); plt.plot(dates, prices); plt.title('Google Stock Price'); plt.xlabel('Date'); plt.ylabel('Stock Price $'); plt.show()"

Note that you could easily add text and lines to the plot, as date-time string coordinates are allowed in most plotting functions.

Main Guide, Datetime Menu

Candlestick Plot

For this kind of plot, use the function candlestick(), which requires a list of date-time strings and a dictionary with the following 'Open', 'Close', 'High', and 'Low' mandatory keys, and where each correspondent value is a list of prices.

Here is an example, which requires the package yfinance:

import yfinance as yf
import plotext as plt

plt.date_form('d/m/Y')

start = plt.string_to_datetime('11/04/2022')
end = plt.today_datetime()
data = yf.download('goog', start, end)

dates = plt.datetimes_to_string(data.index)

plt.candlestick(dates, data)

plt.title("Google Stock Price CandleSticks")
plt.xlabel("Date")
plt.ylabel("Stock Price $")
plt.show()

or directly on terminal:

python3 -c "import yfinance as yf; import plotext as plt; plt.date_form('d/m/Y'); start = plt.string_to_datetime('11/04/2022'); end = plt.today_datetime(); data = yf.download('goog', start, end); dates = plt.datetimes_to_string(data.index); plt.candlestick(dates, data); plt.title('Google Stock Price Candlesticks'); plt.xlabel('Date'); plt.ylabel('Stock Price $'); plt.show()"

More documentation can be accessed with doc.candlestick().

Main Guide, Datetime Menu