?
Plost

A deceptively simple plotting library for Streamlit.

Because you’ve been writing plots wrong all this time.

Getting started

pip install plost

Basics

Plost makes it easy to build common plots using the Vega-Lite library but without having to delve into Vega-Lite specs (unless you’re doing something tricky), and without having to melt your DataFrame from long format to wide format (the bane of most Vega-Lite plots!)

For example, let’s say you have a “long-format” table like this:

time	stock_name	stock_value
…	stock1	1
…	stock2	2
…	stock1	100
…	stock2	200

Then you can draw a line chart by simply calling line_chart() with some column names:

import plost

plost.line_chart(
  my_dataframe,
  x='time',  # The name of the column to use for the x axis.
  y='stock_value',  # The name of the column to use for the data itself.
  color='stock_name', # The name of the column to use for the line colors.
)

Simple enough! But what if you instead have a “wide-format” table like this, which is super common in reality:

time	stock1	stock2
…	1	100
…	2	200

Normally you’d have to melt() the table with Pandas first or create a complex Vega-Lite layered plot. But with Plost, you can just specify what you’re trying to accomplish and it will melt the data internally for you:

import plost

plost.line_chart(
  my_dataframe,
  x='time',
  y=('stock1', 'stock2'),  # ? This is magic!
)

Ok, now let’s add a mini-map to make panning/zooming even easier:

import plost

plost.line_chart(
  my_dataframe,
  x='time',
  y=('stock1', 'stock2'),
  pan_zoom='minimap',  # ? This is magic!
)

But we’re just scratching the surface. Basically the idea is that Plost allows you to make beautiful Vega-Lite-driven charts for your most common needs, without having to learn about the powerful yet complex language behind Vega-Lite.

Check out the the sample app / docs for a taste of other amazing things you can do!