kx-plot

One-line matplotlib plots and themes for notebooks and scripts.

kx is a small, plain-Python package with .mplstyle themes, palettes and colourmaps. It needs nothing beyond matplotlib, numpy and pandas and works offline, so it also runs in Kaggle competition notebooks.

Install

pip install kx-plot

import kx; kx.use('dark')

Kaggle

Attach the dataset instead (Add Input → Datasets → vhrabar/kx-plot), then:

import sys; sys.path.append('/kaggle/input/datasets/vhrabar/kx-plot')
import kx; kx.use('dark')

Usage

kx.use('light', palette='okabe', cmap='cividis')   # notebook default: theme, palette, colormap
kx.plot(x, y, z, 'scatter-grid-leg')               # spec: kind-theme-flag-...
kx.plot(x, y, 'bar-paper')                         # a theme in the spec applies to this plot only
with kx.context('paper'): ...                      # or to every plot in the block
kx.save('fig.png')                                 # to /kaggle/working on Kaggle, else the current folder
for ax, col in zip(kx.grid(3), df.columns):        # a figure of 3 panels, a flat array of axes
    kx.plot(df, col, spec='hist', ax=ax)
kx.plot(df, 'month', 'y2025', 'bar')               # DataFrame columns by name
kx.plot(x, y, 'line', linewidth=3)                 # other keywords go to matplotlib
kx.plot(df, 'value', spec='kde', by='group')       # one density curve per group
kx.plot(df.value, spec='box', by=df.group)         # one box per group (also ridge, violin, qq)

stack works with area, bar, barh and hist. norm is a 100% stack for area and a density (area 1) for hist. cum makes hist cumulative; hist-norm-cum is the CDF. hist puts every series on the same bins, so the bars line up. diag adds a dashed y = x line to scatter and hexbin; fit adds a least-squares line to scatter, with its slope and R² in the legend (one line per group with a categorical z).

Unknown tokens raise an error instead of being guessed, with the closest valid tokens as a hint. Everything is inspectable: kx.grammar(), kx.grammar('area'), kx.parse('leg-scatter'), kx.show('dark'), kx.source('scatter').

Tables

kx.load('passengers') is a demo table with numbers, categories and NaNs to try these on.

kx.missing(df)                                     # share of NaNs per column, the most missing on top
kx.plot(df, 'nullmap-sort')                        # where the NaNs are: one pixel row per table row
kx.plot(df, 'heat-corr-ann')                       # correlations of the numeric columns, -1 to 1
kx.plot(df, 'heat')                                # any numeric DataFrame or 2-D array as coloured cells
kx.plot(df, 'pclass', spec='count', by='survived') # rows per category, split by a second column
kx.plot(df, 'pclass', 'port', 'crosstab-norm-ann') # how often each pair of categories occurs
kx.plot(df, 'age', 'fare', 'hexbin-logc')          # points per hexagon; with a z, its mean per hexagon

heat, missing and nullmap take the whole table and no column names; kx.plot(df[cols], 'heat') for some columns. wrap breaks long tick labels onto several lines.

Machine learning

kx.load('binary'), 'multiclass', 'regression', 'history', 'importance' and 'curves' are demo data for these kinds. Metrics are computed in numpy: no scikit-learn needed.

kx.plot(y_true, score, 'roc')                      # ROC curve, AUC in the legend
kx.plot(y_true, gbm, logreg, 'pr')                 # a second model goes in z; AP and a random baseline
kx.plot(y_true, proba_df, 'roc')                   # a 2-D score: one curve per class, one-vs-rest
kx.plot(y_true, score, 'calib')                    # reliability diagram, Brier score in the legend
kx.plot(y_true, score, 'proba')                    # score histogram per true class
kx.plot(y_true, score, 'thresh-best')              # precision, recall and F1 against the threshold
kx.plot(y_true, score, 'gain')                     # also 'lift'
kx.plot(y_true, y_pred, 'cm-norm-ann')             # confusion matrix, each row the recall of a class
kx.plot(actual, predicted, 'pva')                  # predicted vs actual, R², RMSE and MAE
kx.plot(actual, predicted, feature, 'resid')       # residuals, coloured by a feature
kx.plot(df, 'feature', 'importance', 'std', 'imp') # feature importance with error bars, top= 20
kx.plot(model.fit(...), 'loss-best')               # training curves from a Keras History, dict or DataFrame
kx.plot(sizes, train_scores, val_scores, 'lcurve') # scikit-learn's learning_curve output; also 'vcurve'
kx.plot(ks, inertia, silhouette, 'elbow-best')     # choosing k, the knee marked
kx.roc_auc(y_true, score), kx.pr_ap(y_true, score) # the metrics as numbers
kx.evaluate(y_true, gbm, logreg)                   # a report: the panels picked from the data

The truth comes first, then the predictions. Binary labels are 0/1 or bool, with 1/True the positive class; with two other labels the later one in sorted order is positive. For multiclass, pass a 2-D score with one column per class: the class names are the DataFrame's columns, or else the sorted labels of y_true. roc, pr, calib, gain and lift draw their legend without leg, because the metric in it is the point of the plot.

kx.evaluate(y_true, *scores) draws roc, pr, calib and proba for a binary task, roc, cm and proba for a 2-D score, and pva, resid and a residual hist for a numeric y with many values. It returns the flat array of axes, like kx.grid; spec='dark-grid' styles every panel.

rcParams can be overridden in kx.use with __ for dots: kx.use('dark', figure__figsize=(8, 4)).

Every kind, option, flag and config, with its output, is in the Example Usage notebook.

Palettes

Palettes for kx.use(theme, palette=...), they swap only the colours; a theme's other cycled properties (such as paper's linestyles) stay.

kx.palette('okabe') returns the hex codes. A list of colours works too: palette=['#264653', '#e9c46a'].

Colourmaps

Colourmaps for kx.use(theme, cmap=...) colour continuous values, such as a numeric z in scatter. Without cmap, the theme's own default applies. Add _r to any name to reverse it, e.g. cmap="thermal_r".

kx.cmaps() lists the ones that are available in the installed matplotlib as those implemented in matplotlib 3.10 or newer are not vendored.

License

Released under the MIT License. See LICENSE.

Copyright © 2026 Vedran Hrabar

Vendored palettes and colourmaps keep their own licences; see kx/styles/palettes/LICENCES.md and kx/styles/cmaps/LICENCES.md.