import numpy as np
import matplotlib.pyplot as plt

plt.figure(figsize=(9,9))

# 环形饼图元素
recipe = ["225g flour",
          "90g sugar",
          "1 egg",
          "60g butter",
          "100ml milk",
          "1/2package of yeast"]

# ⽐例
data = [225, 90, 50, 60, 100, 5]

wedges, texts = plt.pie(data,startangle=40)
bbox_props = dict(boxstyle="square,pad=0.3", fc="w", ec="k", lw=0.72)

kw = dict(arrowprops=dict(arrowstyle="-"),
          bbox=bbox_props,va="center")

for i, p in enumerate(wedges):
    ang = (p.theta2 - p.theta1)/2. + p.theta1 # ⻆度计算
    
    # ⻆度转弧度----->弧度转坐标
    y = np.sin(np.deg2rad(ang))
    x = np.cos(np.deg2rad(ang))
    ha = {-1: "right", 1: "left"}[int(np.sign(x))] # ⽔平对⻬⽅式
    connectionstyle = "angle,angleA=0,angleB={}".format(ang) # 箭头连接样式
    kw["arrowprops"].update({"connectionstyle": connectionstyle}) # 更新箭头连接⽅式
    plt.annotate(recipe[i], xy=(x, y), xytext=(1.35*np.sign(x), 1.4*y),
                 ha=ha,**kw,fontsize = 18,weight = 'bold')
    
plt.title("Matplotlib bakery: A donut",fontsize = 18,pad = 25)
plt.tight_layout()
 

填写自己的mysql连接方式和sql语句即可实现饼图带百分比,线长度自己可以调参数
 import pymysql
 from matplotlib import pyplot as plt
 
import numpy as np
 
class mysql_func():
 # 配置mysql数据库连接池
 def init(self, host=’’, user=’’, password=’’, port=, database=’’,
 charset=’’):
 self.host = host
 self.user = user
 self.password = password
 self.port = port
 self.database = database
 self.charset = charset
 self.db = pymysql.connect(host=host, user=user, password=password, port=port, database=database,
 charset=charset)
 
# 取数据，tuple类型返回
def get_data(self, sql):
    self.curors = self.db.cursor()
    self.curors.execute(sql)
    self.db.commit()
    data = self.curors.fetchall()
    self.curors.close()
    return data

# 存数据,int类型返回成功条数
def get_row_number(self, sql, data=None):
    self.curors = self.db.cursor()
    if data is None or len(data) == 0:
        self.curors.execute(sql)
    else:
        if type(data[0]) != type([]):
            data = [data]
        self.curors.executemany(sql, data)
    self.db.commit()
    data = self.curors.rowcount
    self.curors.close()
    return data

# 取数据,[dict]类型返回
def get_json(self, sql):
    self.curors = self.db.cursor()
    self.curors.execute(sql)
    self.db.commit()
    columns = [col[0] for col in self.curors.description]
    data = [dict(zip(columns, row)) for row in self.curors.fetchall()]
    self.curors.close()
    return data
 
def academic_co_country_img():
 mysql_aliyun = mysql_func(host=’’, user=’’, password=’’, port=,
 database=’’)
 sql = ‘’’’’’
 country_data = mysql_aliyun.get_data(sql)
 print(country_data)
 fig, ax = plt.subplots(figsize=(10, 6), subplot_kw=dict(aspect=“equal”))
 size = 0.3
 vals = np.array([[k[1],0] for k in country_data])
 # print(vals.sum())
 ingredients = [k[0] for k in country_data]
 print(ingredients)
 recipe = []
 for k in country_data:
 recipe.append(k[1]/vals.sum())
 # recipe.append(format(k[1]/vals.sum(),’.1%’))
 # print(recipe)
 new_ingredients = []
 for l in range(len(ingredients)):
 new_ingredients.append(ingredients[l] + " " + str(format(recipe[l],’.1%’)))
 print(new_ingredients)
 
new_data = []
qita_num = 0
data = [k[1] for k in country_data]
if len(data) >= 10:
    for d in range(len(data)):
        if d > 9:
            new_data.append(data[d])
            qita_num += data[d]
    new_data.append(qita_num)
else:
    new_data = data
print(new_data,"************************")
wedges, texts = ax.pie(data, wedgeprops=dict(width=0.3), startangle=-40)
ax.legend(new_ingredients, title="", loc="upper left", bbox_to_anchor=(1, 0, 0.5, 1), )

# 每一类别说明框
# boxstyle框的类型，fc填充颜色,ec边框颜色,lw边框宽度
bbox_props = dict(boxstyle="square,pad=0.3", fc='white', ec="white", lw=0.72)
# 设置框引出方式
kw = dict(arrowprops=dict(arrowstyle="-"),
          bbox=bbox_props, zorder=0, va="center")

# 添加标签
ta = 1.4
for i, p in enumerate(wedges):
    # if recipe[i] >= 0.03:
    if i < 10:
        ang = (p.theta2 - p.theta1) / 2. + p.theta1
        y = np.sin(np.deg2rad(ang))
        x = np.cos(np.deg2rad(ang))
        # 设置方向
        horizontalalignment = {-1: "right", 1: "left"}[int(np.sign(x))]
        connectionstyle = "angle,angleA=0,angleB={}".format(ang)
        kw["arrowprops"].update({"connectionstyle": connectionstyle})
        #设置标注 这一步可以调整饼图的线
        ax.annotate(format(recipe[i],'.1%'), xy=(x, y), xytext=(1.35 * np.sign(x), 1.4 * y),
                    horizontalalignment=horizontalalignment, color='black', **kw)
        ta -= 0.3

ax.set_title("    ")

plt.show()
'''
cmap = plt.get_cmap("tab20c")
outer_colors = cmap(np.arange(3) * 4)

wedges = ax.pie(vals.sum(axis=1), wedgeprops=dict(width=0.5), startangle=-40, autopct='%.1f%%',radius=1, pctdistance=1.2, labeldistance=1.2)

ax.legend(ingredients, title="", loc="upper left", bbox_to_anchor=(1, 0, 0.5, 1),)

ax.set(aspect="equal", title='')
plt.show()
'''
 
if name == ‘main’:
 academic_co_country_img()

 

 
I have produced a very simple pie chart in Python using Matplotlib and I am wanting to edit the alignment of my labels. I have used \n within my labels to split the line as the labels are too long for one line. But as you can see from the picture called 'pie chart image', it's a mix of weird alignments at the moment. I would really like to have it center alignment.
 
For other chart/graph types in Matplotlib there is an argument called align where you can set it to center, however, plt.pie(...) does not seem to have this attribute.
 
Here is my code:
 
import matplotlib.pyplot as plt
 
k = [7,15]
 
labels = 'Strongly and Mostly \n Agree', 'Strongly/Mostly Disagree \n and In the Middle'
 
plt.pie(k, labels= labels)
 
plt.show()
 

 
Any ideas?
 
解决方案
 
You can pass a dictionary of text properties to plt.pie via the textprops argument. For example:
 
plt.pie(k, labels=labels, textprops={'weight': 'bold'})
 
However, if you try to specify the horizontalalignment property, you'll get an error saying that you provided that parameter twice. Obviously you didn't, but matplotlib passed both it's hard-coded value and your value to some internal function.
 
But that's probably a good thing. The way I see it, there's not so much a mix of alignments, but a consistent alignment of the text against the pie.
 
Back to your question
 
pie returns both the patches and the labels for each wedge. So you can loop through the labels after your initial call to pie to modify their alignment. That looks like this:
 
k = [7, 15]
 
labels = 'Strongly and Mostly\nAgree', 'Strongly/Mostly Disagree\nand In the Middle'
 
fig, ax = plt.subplots()
 
ax.set_aspect('equal')
 
wedges, labels = ax.pie(k, labels=labels, textprops={'weight': 'bold'})
 
for label in labels:
 
label.set_horizontalalignment('center')
 

 
As you can see, the labels now overlap with the wedges, diminishing legibility.
 
The labels also have a set_position method (i.e., label.set_position((x, y))), but recomputing the positions for N labels in a pie chart sounds like a Bad Time to me.

改变饼图使用autopct设置百分比显示后的位置
 
 
 
 
可以看到环状图上的百分比数字位置显示看的很不舒服，想让数据离中心远一点
 
 
在pie中使用pctdistance参数