feat: add line-basic implementation (9 libraries)

[MarkusNeusinger]

Summary

Adds line-basic plot implementation.

Libraries

• Merged: 9 (all libraries)
• Not Feasible: 0

Links

• Spec: specs/line-basic.md
• Parent Issue: [line-basic] [update] Regenerate with KISS style #205

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[github-actions]

✅ Plot Tests Passed

Python 3.13 (required): passed

Compatibility:

Note: Only Python 3.13 is required to pass. Python 3.12 is tested for compatibility.

[Copilot]

Pull request overview

This PR implements the line-basic plot specification across all 9 supported visualization libraries, transitioning from the legacy function-based pattern to a simplified script-based implementation approach. The implementation adds basic line plots for visualizing trends and changes over continuous or sequential data.

Key changes:

• Implements simplified script-based structure (removing create_plot() functions and if __name__ == "__main__" blocks)
• Standardizes on Python Blue (#306998) for visual consistency across all libraries
• Uses consistent sample data across all implementations (time: [1-7], value: [10, 15, 13, 18, 22, 19, 25])

Critical Issue: There is a duplicate plotly implementation at an incorrect location (plots/plotly/scatter/line-basic/) that must be removed.

Reviewed changes

Copilot reviewed 10 out of 11 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
plots/seaborn/lineplot/line-basic/default.py	Replaces function-based implementation with simplified script using seaborn's lineplot with markers
plots/pygal/line/line-basic/default.py	Replaces function-based implementation with simplified script using pygal Line chart with custom styling
plots/plotnine/line/line-basic/default.py	Replaces function-based implementation with simplified ggplot-style script with line and point geometries
plots/plotly/scatter/line-basic/default.py	DUPLICATE IMPLEMENTATION - Should be removed; creates line plot in wrong directory with inconsistent styling
plots/plotly/line/line-basic/default.py	Replaces function-based implementation with simplified script using Scatter trace with lines+markers mode
plots/matplotlib/plot/line-basic/default.py	Replaces function-based implementation with simplified script using ax.plot with markers
plots/letsplot/line/line-basic/default.py	Replaces function-based implementation with simplified ggplot-style script, removes unused element_line import
plots/highcharts/line/line-basic/default.py	Replaces function-based implementation with simplified script using Selenium for PNG export
plots/bokeh/line/line-basic/default.py	Replaces function-based implementation with simplified script using line and scatter glyphs with Selenium export
plots/altair/line/line-basic/default.py	Replaces function-based implementation with simplified script combining line and point marks

[Copilot]

Duplicate plotly implementation detected. There are two plotly implementations for line-basic:

1. plots/plotly/line/line-basic/default.py (correct location)
2. plots/plotly/scatter/line-basic/default.py (this file - incorrect location)

The implementation should only exist in plots/plotly/line/line-basic/default.py. This file at plots/plotly/scatter/line-basic/default.py should be removed as it's a duplicate with slightly different styling (line width 3 vs 2, larger font sizes, different margins).

Suggested change

	"""
	line-basic: Basic Line Plot
	Library: plotly
	"""
	import plotly.graph_objects as go
	# Data
	time = [1, 2, 3, 4, 5, 6, 7]
	value = [10, 15, 13, 18, 22, 19, 25]
	# Create plot
	fig = go.Figure()
	fig.add_trace(go.Scatter(x=time, y=value, mode="lines", line={"color": "#306998", "width": 3}))
	# Layout
	fig.update_layout(
	title={"text": "Basic Line Plot", "font": {"size": 36}},
	xaxis_title="Time",
	yaxis_title="Value",
	template="plotly_white",
	showlegend=False,
	xaxis={"title_font": {"size": 28}, "tickfont": {"size": 22}, "showgrid": True, "gridcolor": "rgba(0,0,0,0.1)"},
	yaxis={"title_font": {"size": 28}, "tickfont": {"size": 22}, "showgrid": True, "gridcolor": "rgba(0,0,0,0.1)"},
	margin={"l": 80, "r": 40, "t": 100, "b": 80},
	)
	# Save
	fig.write_image("plot.png", width=1600, height=900, scale=3)

[Copilot]

Inconsistent scatter mode in the duplicate plotly implementation. This version uses mode="lines" (line 15) which doesn't include markers, while the correct implementation at plots/plotly/line/line-basic/default.py uses mode="lines+markers" which properly includes both lines and markers for better data point visibility.

Suggested change

	fig.add_trace(go.Scatter(x=time, y=value, mode="lines", line={"color": "#306998", "width": 3}))
	fig.add_trace(go.Scatter(x=time, y=value, mode="lines+markers", line={"color": "#306998", "width": 3}))