Python + Matplotlib生成图表

前言：原来准备拿excel生成，奈何30w数据一开excel就崩，所以就去简单学习了一下python。感觉还挺好用，就顺手记录一下。

1. 起因

2. Python连接数据库查询数据转饼图

   import pandas as pd
   import matplotlib.pyplot as plt
   import pymysql
   
   # 联合国儿童基金会
   
   plt.rcParams['font.sans-serif']=['Simhei']
   
   # 连接数据库
   conn = pymysql.connect(host='localhost', port=3306, user='root', password='123456', database='mydb')
   cur = conn.cursor()
   
   # 查询数据
   sql = 'SELECT title, count(*) FROM dpo_import GROUP BY title'
   cur.execute(sql)
   data = cur.fetchall()
   
   # 转换数据
   df = pd.DataFrame(data, columns=['title', 'count'])
   
   # 饼图的标签 可以自定义，这里没用到直接用数据库查询的标签
   labels = ['先生', '女士', '小朋友', '未知']
   # 绘制饼图
   plt.pie(df['count'], labels=df['title'], autopct='%1.2f%%')
   plt.title('人群比例')
   plt.show()
   
   # 关闭数据库连接
   conn.close()
   

3. 捐款人数TOP10

   import pandas as pd
   import matplotlib.pyplot as plt
   import pymysql
   
   # 联合国儿童基金会
   
   plt.rcParams['font.sans-serif']=['Simhei']
   
   # 连接数据库
   conn = pymysql.connect(host='localhost', port=3306, user='root', password='123456', database='mydb')
   cur = conn.cursor()
   
   # 查询数据
   sql = 'SELECT city, count(*) as counts FROM dpo_import  GROUP BY city  ORDER BY counts DESC LIMIT 0, 10'
   cur.execute(sql)
   data = cur.fetchall()
   
   # 转换数据
   df = pd.DataFrame(data, columns=['city', 'count'])
   
   # 绘制饼图
   plt.bar(df['city'], df['count'])
   plt.title('捐款地区TOP10')
   plt.show()
   
   # 关闭数据库连接
   conn.close()