pandas操作excel操作-20-操作数据库-复杂函数的使用

读取数据库

import pandas as pd
import pyodbc
import sqlalchemy

connection = pyodbc.connect('{driver_url}')
engine = sqlalchemy.create_engine('{driver_url}')

query_sql = 'select * from user'

df1 = pd.read_sql_query(query_sql, connection)
df2 = pd.read_sql_query(query_sql, engine)

复杂函数的使用，结构化编写复杂函数

import pandas as pd
import numpy as np

def get_circumcircle_area(l, h):
	r = np.sqrt(l ** 2 + h ** 2)/2
	return r ** 2 * np.pi

def wrapper(row):
	return get_circumcircle_area(row['Length'], row['Height'])

rects = pd.read_excel('C:/rects.xlsx', index_col='ID')
rects['CA'] = rects.apply(wrapper, axis=1)
print(rects)

来源：oschina

链接：https://my.oschina.net/ski/blog/3183044