Python Charts

Python plotting and visualization demystified

Matplotlib

Move X-Axis or Y-Axis Spines to the Center in Matplotlib

Move Matplotlib x-axis and y-axis spines to the center of a chart.

TL;DR

Move the left and bottom spines to the zero coordinates, then hide the opposite spines:

fig, ax = plt.subplots()
ax.plot(x, y)

ax.spines["left"].set_position("zero")
ax.spines["bottom"].set_position("zero")
ax.spines["right"].set_visible(False)
ax.spines["top"].set_visible(False)

plt.show()

Matplotlib sine wave with x-axis and y-axis spines centered at zero

This is useful for functions, coordinate plots, and charts where zero should be the visual origin.

Move Only One Spine

Center just the x-axis or y-axis by moving one spine:

ax.spines["bottom"].set_position("zero")  # x-axis at y=0
ax.spines["left"].set_position("zero")    # y-axis at x=0

Move a Spine to Another Data Value

Use ("data", value) to position a spine at a different coordinate:

ax.spines["bottom"].set_position(("data", 5))
ax.spines["left"].set_position(("data", 10))

The first line moves the x-axis to y=5; the second moves the y-axis to x=10.

Keep Tick Labels on the Moved Spines

Matplotlib usually keeps the ticks with their spine. If you need to explicitly place them, use:

ax.xaxis.set_ticks_position("bottom")
ax.yaxis.set_ticks_position("left")