Py Plotting

Python Plotting

Library Decision

Quick Start

Plotly Express (most common):

import plotly.express as px

fig = px.scatter(df, x="col_a", y="col_b", color="category",
                 title="My Chart", template="plotly_white")
fig.show()                          # interactive in notebook/browser
fig.write_html("chart.html")        # shareable standalone file
fig.write_image("chart.png", scale=2)  # high-res static (requires kaleido)

matplotlib (static):

import matplotlib.pyplot as plt
import matplotlib as mpl

mpl.rcParams.update({"font.family": "sans-serif", "figure.dpi": 150})

fig, ax = plt.subplots(figsize=(8, 5))
ax.plot(x, y, color="#4C78A8", linewidth=2, label="Series A")
ax.set(title="My Chart", xlabel="X", ylabel="Y")
ax.legend(frameon=False)
ax.spines[["top", "right"]].set_visible(False)
plt.tight_layout()
plt.savefig("chart.png", dpi=300, bbox_inches="tight")

Aesthetics Quick Reference

Plotly templates (set via template=):

• "plotly_white" — clean white background (general use)
• "plotly_dark" — dark theme (presentations)
• "seaborn" — seaborn-inspired style
• "ggplot2" — R ggplot2-inspired style
• "simple_white" — minimal, publication-friendly

Plotly color sequences (set via color_discrete_sequence=):

• px.colors.qualitative.Safe — colorblind-safe categorical
• px.colors.qualitative.Plotly — default Plotly palette
• px.colors.sequential.Viridis — sequential (maps, heatmaps)

matplotlib style shortcuts:

plt.style.use("seaborn-v0_8-whitegrid")   # clean grid style
plt.style.use("bmh")                        # Bayesian Methods for Hackers style

Plotly Layout Polish

fig.update_layout(
    font_family="Inter, Arial, sans-serif",
    title_font_size=18,
    margin=dict(l=40, r=20, t=60, b=40),
    legend=dict(orientation="h", yanchor="bottom", y=1.02, xanchor="right", x=1),
    plot_bgcolor="white",
    paper_bgcolor="white",
)
fig.update_xaxes(showgrid=True, gridcolor="#EEEEEE", zeroline=False)
fig.update_yaxes(showgrid=True, gridcolor="#EEEEEE", zeroline=False)

Hover Templates (Plotly)

fig.update_traces(
    hovertemplate="<b>%{x}</b><br>Value: %{y:,.0f}<extra></extra>"
)

Common Chart Patterns

See the reference files for detailed patterns and examples:

• references/plotly-charts.md — Plotly chart recipes: scatter, line, bar, histogram, box, heatmap, subplots, animations
• references/matplotlib-charts.md — matplotlib chart recipes: line, bar, histogram, heatmap, subplots, twin axes, annotations

Output & Sharing

Install kaleido for Plotly static export: pip install kaleido