如何在plt.show()后保留/恢复Matplotlib上下文以生成包含新增数据的多幅图表

云原生阿岚

2026-4-30

Solution to Preserve Plot Context After plt.show()

Got it, let's break down how to fix this! The core issue is that when you call plt.show() in Matplotlib, it automatically closes the current figure and clears its associated axes by default. That’s why your second plt.plot() starts fresh instead of building on the first plot’s data.

Since you want two independent figures (not an updated single plot), here are two simple, effective approaches:

Option 1: Save Your Data and Replot for the Second Figure

This is the most straightforward method—just store your first dataset so you can reuse it when creating the second figure.

import matplotlib.pyplot as plt

# First figure: only show [1,2,3]
data_first = [1, 2, 3]
plt.plot(data_first)
plt.show()

# Second figure: show both datasets
plt.plot(data_first)
plt.plot([3, 2, 1])
plt.show()

Option 2: Use Matplotlib's Object-Oriented API (Recommended)

For more control over your plots, use Matplotlib's object-oriented interface. This lets you explicitly create and manage separate figure/axes pairs, so you never lose track of your plot context.

import matplotlib.pyplot as plt

# Create first figure and axes, plot the first dataset
fig1, ax1 = plt.subplots()
ax1.plot([1, 2, 3])
plt.show()

# Create second figure and axes, plot both datasets
fig2, ax2 = plt.subplots()
ax2.plot([1, 2, 3])
ax2.plot([3, 2, 1])
plt.show()

Both approaches will give you exactly what you want: