novem - data visualisation for coders

A wrapper library for the novem.io data visualisation platform. Create charts, documents, e-mails and dashboards through one simple API.

NB: novem is currently in closed alpha, if you want to try it out please reach out to hello@novem.io

Examples

Create a linechart from a pandas dataframe (assumes a configured profile — see "Getting started" below).

import numpy as np
import pandas as pd
from novem import Plot

# a sample price-like series; swap in your own dataframe. Name the index and
# series so the CSV has a proper "Date,Price" header.
dates = pd.date_range("2015-01-01", "2021-12-31", freq="B", name="Date")
prices = pd.Series(
    100 + np.random.randn(len(dates)).cumsum(), index=dates, name="Price"
)

line = Plot("price_hist", type="line", name="Sample price history")

# send data to the plot
prices.pipe(line)

# url to view the plot
print(line.url)

Getting started

To get started with novem you will have to register an account. Please reach out to us!

Once you have a username and password you can setup your environment using:

  python -m novem --init

In addition to invoking the novem module as shown above, the novem package also includes an extensive command-line interface (cli). Check out CLI.md in this repository or novem.io for more details.

Configuration and authentication

Every novem object needs a token and an API root to talk to the platform. These are resolved, in order of precedence, from:

1. explicit keyword arguments on the object (or a Session, see below)
2. values set programmatically via novem.config
3. the NOVEM_TOKEN / NOVEM_API_ROOT environment variables
4. the config file written by python -m novem --init

The simplest setup is the config file (--init above). To configure novem programmatically instead — handy in notebooks, scripts or CI — set a token on the global novem.config object once, and objects created afterwards pick it up automatically:

import novem

novem.config.set_token("your-token")

plot = novem.Plot("my-plot")

novem.config also exposes set_api_root(...) (to point at a non-default API) and use_profile(...) (to select a profile from the config file).

Alternatively, pass the token straight to the object. An explicit argument always wins over whatever is on novem.config:

plot = novem.Plot("my-plot", token="your-token")

Multiple accounts / profiles

A Session captures connection settings (token, api_root or a config-file profile) and constructs objects bound to them, without touching the global defaults — useful when working against several accounts at once:

import novem

work = novem.Session(profile="work")
personal = novem.Session(profile="personal")

# copy a plot's data from one account to the other
personal.Plot("earnings").data = work.Plot("earnings").data

Creating a plot

Novem represents plots as a Plot class that can be imported from the main novem package from novem import Plot.

The Plot class takes a single mandatory positional argument, the name of the plot.

• If the plot name is new, the instantiation of the class will create the plot.
• If the plot name already exist, then the new object will operate on the existing plot.

In addition to the name, there are two broad categories of options for a plot: data and config.

• The data contains the actual information to visualise (usually in the form of numeric csv)
• Config, which contains information about the visual such as:
  • Type (bar, line, donut, map etc)
  • Titles/captions/names/colors/legends/axis etc

There are two ways to interact with the plots, one can either supply all the necessary options as named arguments when creating the plot, or use the property accessors to modify them one by one (this is more helpful when working with the plot interactively). Below is an example of both approaches.

from novem import Plot

# everything in the constructor
barchart = Plot(<name>, \
  type="bar", \
  title="barchart title", \
  caption = "caption"
)

# property approach
barchart = Plot("plot_name")
barchart.type = "bar"
barchart.title = "barchart title"
barchart.caption = "caption"

In addition to setting individual properties, the Plot object is also callable. This means that the resulting plot can be used as a function, either by being provided data as an argument, or used as part of a pipe chain.

from novem import Plot
import pandas as pd
import numpy as np

# construct some random sample data
df = pd.DataFrame(np.random.randn(100, 4), columns=list("ABCD")).cumsum()

line = Plot("new_line", type="line")

# alternative one, setting data explicitly to a csv string
line.data = df.to_csv()

# or let the plot invoke the to_csv
line.data = df

# alternative two, calling Plot with a csv string
line(df.to_csv())

# alternative three calling the Plot with an object that has a to_csv function
line(df)

# or
df.pipe(line)

NB: All novem plot operations are live. This means that as soon as you write to or modify any aspects of the plot object, those changes are reflected on the novem server and anyone watching the plot in real time.

Contribution and development

The novem python library and platform is under active development, contributions or issues are most welcome.

For guidelines on how to contribute, please check out the CONTRIBUTING.md file in this repository.

LICENSE

This python library is licensed under the MIT license, see the LICENSE file for details.