python matplotlib實現(xiàn)將圖例放在圖外

更新時間：2020年04月17日 11:38:00 作者：Johnson0722

這篇文章主要介紹了python matplotlib實現(xiàn)將圖例放在圖外，具有很好的參考價值，希望對大家有所幫助。一起跟隨小編過來看看吧

關于matplotlib如何設置圖例的位置？如何將圖例放在圖外？以及如何在一幅圖有多個子圖的情況下，刪除重復的圖例？我用一個簡單的例子說明一下。

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt

fig = plt.figure(1)
ax1 = fig.add_subplot(2,2,1)
ax2 = fig.add_subplot(2,2,2)
ax3 = fig.add_subplot(2,2,3)
ax4 = fig.add_subplot(2,2,4)

df1 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])
df2 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])
df3 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])
df4 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])

df1.plot(ax = ax1, title = "df1", grid = 'on')
df2.plot(ax = ax2, title = "df1", grid = 'on')
df3.plot(ax = ax3, title = "df1", grid = 'on')
df4.plot(ax = ax4, title = "df1", grid = 'on')

plt.show()

運行結果如下

可以看出，隨機生成了幾個dataframe,在一個figure()中生成了四個子圖，每個子圖的圖例都是dataframe.columns里的值，那么如何移除這些圖例？

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt

fig = plt.figure(1)
ax1 = fig.add_subplot(2,2,1)
ax2 = fig.add_subplot(2,2,2)
ax3 = fig.add_subplot(2,2,3)
ax4 = fig.add_subplot(2,2,4)

df1 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])
df2 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])
df3 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])
df4 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])

df1.plot(ax = ax1, title = "df1", grid = 'on')
df2.plot(ax = ax2, title = "df1", grid = 'on')
df3.plot(ax = ax3, title = "df1", grid = 'on')
df4.plot(ax = ax4, title = "df1", grid = 'on')

ax1.legend_.remove()  ##移除子圖ax1中的圖例
ax2.legend_.remove()  ##移除子圖ax2中的圖例
ax3.legend_.remove()  ##移除子圖ax3中的圖例

plt.show()

可以看出ax1,ax2,ax3中的圖例都被移除了，但是上圖還不是很美觀？有沒有什么辦法將圖例放到圖外面呢？請看:

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt

fig = plt.figure(1)
ax1 = fig.add_subplot(2,2,1)
ax2 = fig.add_subplot(2,2,2)
ax3 = fig.add_subplot(2,2,3)
ax4 = fig.add_subplot(2,2,4)

df1 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])
df2 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])
df3 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])
df4 = pd.DataFrame(np.random.randn(3,5),columns = ['one','two','three','four','five'])

df1.plot(ax = ax1, title = "df1", grid = 'on')
df2.plot(ax = ax2, title = "df1", grid = 'on')
df3.plot(ax = ax3, title = "df1", grid = 'on')
df4.plot(ax = ax4, title = "df1", grid = 'on')

ax1.legend_.remove()
ax2.legend_.remove()
ax3.legend_.remove()
ax4.legend(loc=2, bbox_to_anchor=(1.05,1.0),borderaxespad = 0.)  ##設置ax4中l(wèi)egend的位置，將其放在圖外

plt.show()