对http://matplotlib.org/users/shell.html:中提供的示例进行了轻微编辑

import numpy as np
import matplotlib.pyplot as plt

fig = plt.figure()
ax = fig.add_subplot(111)
ax.set_title('click on points')

line, = ax.plot(np.random.rand(100), '-', picker=5)  # 5 points tolerance


def onpick(event):
    thisline = event.artist
    xdata = thisline.get_xdata()
    ydata = thisline.get_ydata()
    ind = event.ind
    print('onpick points:', *zip(xdata[ind], ydata[ind]))


fig.canvas.mpl_connect('pick_event', onpick)

plt.show()

就像Sohaib问的，这是一条直线

其他答案没有解决我在最新版本的Jupyter内联matplotlib图中正确显示工具提示的需求。这条是可行的:

import matplotlib.pyplot as plt
import numpy as np
import mplcursors
np.random.seed(42)

fig, ax = plt.subplots()
ax.scatter(*np.random.random((2, 26)))
ax.set_title("Mouse over a point")
crs = mplcursors.cursor(ax,hover=True)

crs.connect("add", lambda sel: sel.annotation.set_text(
    'Point {},{}'.format(sel.target[0], sel.target[1])))
plt.show()

当用鼠标浏览一个点时，会导致如下图所示:

对http://matplotlib.org/users/shell.html:中提供的示例进行了轻微编辑

import numpy as np
import matplotlib.pyplot as plt

fig = plt.figure()
ax = fig.add_subplot(111)
ax.set_title('click on points')

line, = ax.plot(np.random.rand(100), '-', picker=5)  # 5 points tolerance


def onpick(event):
    thisline = event.artist
    xdata = thisline.get_xdata()
    ydata = thisline.get_ydata()
    ind = event.ind
    print('onpick points:', *zip(xdata[ind], ydata[ind]))


fig.canvas.mpl_connect('pick_event', onpick)

plt.show()

就像Sohaib问的，这是一条直线

Mplcursors对我很有用。Mplcursors为matplotlib提供了可单击的注释。它很大程度上受到mpldatacursor (https://github.com/joferkington/mpldatacursor)的启发，具有非常简化的API

import matplotlib.pyplot as plt
import numpy as np
import mplcursors

data = np.outer(range(10), range(1, 5))

fig, ax = plt.subplots()
lines = ax.plot(data)
ax.set_title("Click somewhere on a line.\nRight-click to deselect.\n"
             "Annotations can be dragged.")

mplcursors.cursor(lines) # or just mplcursors.cursor()

plt.show()

基于Markus Dutschke”和“ImportanceOfBeingErnest”，我简化了代码，使其更加模块化。

此外，这也不需要安装额外的包。

import matplotlib.pylab as plt
import numpy as np

plt.close('all')
fh, ax = plt.subplots()

#Generate some data
y,x = np.histogram(np.random.randn(10000), bins=500)
x = x[:-1]
colors = ['#0000ff', '#00ff00','#ff0000']
x2, y2 = x,y/10
x3, y3 = x, np.random.randn(500)*10+40

#Plot
h1 = ax.plot(x, y, color=colors[0])
h2 = ax.plot(x2, y2, color=colors[1])
h3 = ax.scatter(x3, y3, color=colors[2], s=1)

artists = h1 + h2 + [h3] #concatenating lists
labels = [list('ABCDE'*100),list('FGHIJ'*100),list('klmno'*100)] #define labels shown

#___ Initialize annotation arrow
annot = ax.annotate("", xy=(0,0), xytext=(20,20),textcoords="offset points",
                    bbox=dict(boxstyle="round", fc="w"),
                    arrowprops=dict(arrowstyle="->"))
annot.set_visible(False)

def on_plot_hover(event):
    if event.inaxes != ax: #exit if mouse is not on figure
        return
    is_vis = annot.get_visible() #check if an annotation is visible
    # x,y = event.xdata,event.ydata #coordinates of mouse in graph
    for ii, artist in enumerate(artists):
        is_contained, dct = artist.contains(event)

        if(is_contained):
            if('get_data' in dir(artist)): #for plot
                data = list(zip(*artist.get_data()))
            elif('get_offsets' in dir(artist)): #for scatter
                data = artist.get_offsets().data

            inds = dct['ind'] #get which data-index is under the mouse
            #___ Set Annotation settings
            xy = data[inds[0]] #get 1st position only
            annot.xy = xy
            annot.set_text(f'pos={xy},text={labels[ii][inds[0]]}')
            annot.get_bbox_patch().set_edgecolor(colors[ii])
            annot.get_bbox_patch().set_alpha(0.7)
            annot.set_visible(True)
            fh.canvas.draw_idle()
        else:
             if is_vis:
                 annot.set_visible(False) #disable when not hovering
                 fh.canvas.draw_idle()

fh.canvas.mpl_connect('motion_notify_event', on_plot_hover)

给出以下结果:

似乎这里的其他答案都不能回答这个问题。这是一个代码，它使用散点并在悬停在散点上时显示注释。

import matplotlib.pyplot as plt
import numpy as np; np.random.seed(1)

x = np.random.rand(15)
y = np.random.rand(15)
names = np.array(list("ABCDEFGHIJKLMNO"))
c = np.random.randint(1,5,size=15)

norm = plt.Normalize(1,4)
cmap = plt.cm.RdYlGn

fig,ax = plt.subplots()
sc = plt.scatter(x,y,c=c, s=100, cmap=cmap, norm=norm)

annot = ax.annotate("", xy=(0,0), xytext=(20,20),textcoords="offset points",
                    bbox=dict(boxstyle="round", fc="w"),
                    arrowprops=dict(arrowstyle="->"))
annot.set_visible(False)

def update_annot(ind):

    pos = sc.get_offsets()[ind["ind"][0]]
    annot.xy = pos
    text = "{}, {}".format(" ".join(list(map(str,ind["ind"]))), 
                           " ".join([names[n] for n in ind["ind"]]))
    annot.set_text(text)
    annot.get_bbox_patch().set_facecolor(cmap(norm(c[ind["ind"][0]])))
    annot.get_bbox_patch().set_alpha(0.4)


def hover(event):
    vis = annot.get_visible()
    if event.inaxes == ax:
        cont, ind = sc.contains(event)
        if cont:
            update_annot(ind)
            annot.set_visible(True)
            fig.canvas.draw_idle()
        else:
            if vis:
                annot.set_visible(False)
                fig.canvas.draw_idle()

fig.canvas.mpl_connect("motion_notify_event", hover)

plt.show()

因为人们还想将这个解决方案用于线状图而不是散点图，所以下面的解决方案将用于图形(其工作方式略有不同)。

import matplotlib.pyplot as plt import numpy as np; np.random.seed(1) x = np.sort(np.random.rand(15)) y = np.sort(np.random.rand(15)) names = np.array(list("ABCDEFGHIJKLMNO")) norm = plt.Normalize(1,4) cmap = plt.cm.RdYlGn fig,ax = plt.subplots() line, = plt.plot(x,y, marker="o") annot = ax.annotate("", xy=(0,0), xytext=(-20,20),textcoords="offset points", bbox=dict(boxstyle="round", fc="w"), arrowprops=dict(arrowstyle="->")) annot.set_visible(False) def update_annot(ind): x,y = line.get_data() annot.xy = (x[ind["ind"][0]], y[ind["ind"][0]]) text = "{}, {}".format(" ".join(list(map(str,ind["ind"]))), " ".join([names[n] for n in ind["ind"]])) annot.set_text(text) annot.get_bbox_patch().set_alpha(0.4) def hover(event): vis = annot.get_visible() if event.inaxes == ax: cont, ind = line.contains(event) if cont: update_annot(ind) annot.set_visible(True) fig.canvas.draw_idle() else: if vis: annot.set_visible(False) fig.canvas.draw_idle() fig.canvas.mpl_connect("motion_notify_event", hover) plt.show()

如果有人正在寻找双轴线的解决方案，请参阅如何使标签出现时悬停在多个轴上的点?

如果有人正在寻找条形图的解决方案，请参考例如这个答案。