I ve written a quick solution, which checks each annotation position against default bounding boxes for all the other annotations. If there is a collision it changes its position to the next available collision free place. It also puts in nice arrows.

For a fairly extreme example, it will produce this (none of the numbers overlap):

Instead of this:

该守则是:

import numpy as np
import matplotlib.pyplot as plt
from numpy.random import *

def get_text_positions(x_data, y_data, txt_width, txt_height):
    a = zip(y_data, x_data)
    text_positions = y_data.copy()
    for index, (y, x) in enumerate(a):
        local_text_positions = [i for i in a if i[0] > (y - txt_height) 
                            and (abs(i[1] - x) < txt_width * 2) and i != (y,x)]
        if local_text_positions:
            sorted_ltp = sorted(local_text_positions)
            if abs(sorted_ltp[0][0] - y) < txt_height: #True == collision
                differ = np.diff(sorted_ltp, axis=0)
                a[index] = (sorted_ltp[-1][0] + txt_height, a[index][1])
                text_positions[index] = sorted_ltp[-1][0] + txt_height
                for k, (j, m) in enumerate(differ):
                    #j is the vertical distance between words
                    if j > txt_height * 2: #if True then room to fit a word in
                        a[index] = (sorted_ltp[k][0] + txt_height, a[index][1])
                        text_positions[index] = sorted_ltp[k][0] + txt_height
                        break
    return text_positions

def text_plotter(x_data, y_data, text_positions, axis,txt_width,txt_height):
    for x,y,t in zip(x_data, y_data, text_positions):
        axis.text(x - txt_width, 1.01*t,  %d %int(y),rotation=0, color= blue )
        if y != t:
            axis.arrow(x, t,0,y-t, color= red ,alpha=0.3, width=txt_width*0.1, 
                       head_width=txt_width, head_length=txt_height*0.5, 
                       zorder=0,length_includes_head=True)

这里是生产这些土地的法典,显示使用:

#random test data:
x_data = random_sample(100)
y_data = random_integers(10,50,(100))

#GOOD PLOT:
fig2 = plt.figure()
ax2 = fig2.add_subplot(111)
ax2.bar(x_data, y_data,width=0.00001)
#set the bbox for the text. Increase txt_width for wider text.
txt_height = 0.04*(plt.ylim()[1] - plt.ylim()[0])
txt_width = 0.02*(plt.xlim()[1] - plt.xlim()[0])
#Get the corrected text positions, then write the text.
text_positions = get_text_positions(x_data, y_data, txt_width, txt_height)
text_plotter(x_data, y_data, text_positions, ax2, txt_width, txt_height)

plt.ylim(0,max(text_positions)+2*txt_height)
plt.xlim(-0.1,1.1)

#BAD PLOT:
fig = plt.figure()
ax = fig.add_subplot(111)
ax.bar(x_data, y_data, width=0.0001)
#write the text:
for x,y in zip(x_data, y_data):
    ax.text(x - txt_width, 1.01*y,  %d %int(y),rotation=0)
plt.ylim(0,max(text_positions)+2*txt_height)
plt.xlim(-0.1,1.1)

plt.show()

Another option using my library adjustText, written specially for this purpose (https://github.com/Phlya/adjustText). I think it s probably significantly slower that the accepted answer (it slows down considerably with a lot of bars), but much more general and configurable.

from adjustText import adjust_text
np.random.seed(2017)
x_data = np.random.random_sample(100)
y_data = np.random.random_integers(10,50,(100))

f, ax = plt.subplots(dpi=300)
bars = ax.bar(x_data, y_data, width=0.001, facecolor= k )
texts = []
for x, y in zip(x_data, y_data):
    texts.append(plt.text(x, y, y, horizontalalignment= center , color= b ))
adjust_text(texts, add_objects=bars, autoalign= y , expand_objects=(0.1, 1),
            only_move={ points :  ,  text : y ,  objects : y }, force_text=0.75, force_objects=0.1,
            arrowprops=dict(arrowstyle="simple, head_width=0.25, tail_width=0.05", color= r , lw=0.5, alpha=0.5))
plt.show()

np.random.seed(2017)
x_data = np.random.random_sample(100)
y_data = np.random.random_integers(10,50,(100))

f, ax = plt.subplots(dpi=300)
bars = ax.bar(x_data, y_data, width=0.001, facecolor= k )
texts = []
for x, y in zip(x_data, y_data):
    texts.append(plt.text(x, y, y, horizontalalignment= center , size=7, color= b ))
adjust_text(texts, add_objects=bars, autoalign= xy , expand_objects=(0.1, 1),
            only_move={ points :  ,  text : y ,  objects : y }, force_text=0.75, force_objects=0.1,
            arrowprops=dict(arrowstyle="simple, head_width=0.25, tail_width=0.05", color= r , lw=0.5, alpha=0.5))
plt.show()

import matplotlib.pyplot as plt

data = [10, 8, 8, 5]

fig = plt.figure()
ax = fig.add_subplot(111)
ax.bar(range(4),data)
ax.set_ylim(0,12)
# extra .4 is because it s half the default width (.8):
ax.text(1.4,8,"2nd bar",rotation=90,va= bottom )
ax.text(2.4,8,"3nd bar",rotation=90,va= bottom )

plt.show()

如果不同说明之间发生碰撞,则从方案上加以确定,是一个更深入的过程。 这个问题可能值得单独讨论:。 Matplotlib text dimensions。

Just thought I would provide an alternative solution that I just created textalloc that makes sure that text-boxes avoids overlap with both each other and lines when possible, and is fast.

举例来说,你可以这样作:

import textalloc as ta
import numpy as np
import matplotlib.pyplot as plt

np.random.seed(2017)
x_data = np.random.random_sample(100)
y_data = np.random.random_integers(10,50,(100))

f, ax = plt.subplots(dpi=200)
bars = ax.bar(x_data, y_data, width=0.002, facecolor= k )
ta.allocate_text(f,ax,x_data,y_data,
            [str(yy) for yy in list(y_data)],
            x_lines=[np.array([xx,xx]) for xx in list(x_data)],
            y_lines=[np.array([0,yy]) for yy in list(y_data)], 
            textsize=8,
            margin=0.004,
            min_distance=0.005,
            linewidth=0.7,
            textcolor="b")
plt.show()

这一结果见。