如何运行 python sqldf 模块里面的静态函数？

Question

我有这段代码可以正常工作：

import pandas as pd
import sqldf
df1 = pd.DataFrame({'col1': [1, 2, 3], 'col2': ['Jhon1', 'Jhon2', 'Jhon3']})
df2 = pd.DataFrame({'col1': [1, 2, 3], 'col2': ['Doe1', 'Doe2', 'Doe3']})
sql_query = '''
select * from df1
left join df2
on df1.col1=df2.col1
'''
result_df = sqldf.run(sql_query)
result_df

然而，当我将它包装在 class 函数中时，如下所示：

import pandas as pd
import sqldf
class MyAmazingClass:
    def static_function():
        df1 = pd.DataFrame({'col1': [1, 2, 3], 'col2': ['Jhon1', 'Jhon2', 'Jhon3']})
        df2 = pd.DataFrame({'col1': [1, 2, 3], 'col2': ['Doe1', 'Doe2', 'Doe3']})
        sql_query = '''
        select * from df1
        left join df2
        on df1.col1=df2.col1
        '''
        result_df = sqldf.run(sql_query)
        return result_df
df = MyAmazingClass.static_function()
df

我收到这个错误：

AttributeError: module 'main' has no attribute 'df2'

如何使此代码在 class 函数中工作？

Answer 1

改用pandasql.sqldf：

import pandas as pd
from pandasql import sqldf
class MyAmaizingClass:
    def static_function():
        df1 = pd.DataFrame({'col1': [1, 2, 3], 'col2': ['Jhon1', 'Jhon2', 'Jhon3']})
        df2 = pd.DataFrame({'col1': [1, 2, 3], 'col2': ['Doe1', 'Doe2', 'Doe3']})
        sql_query = '''
        select * from df1
        left join df2
        on df1.col1=df2.col1
        '''
        result_df = sqldf(sql_query)
        return result_df
MyAmaizingClass.static_function()

输出：

   col1   col2  col1  col2
0     1  Jhon1     1  Doe1
1     2  Jhon2     2  Doe2
2     3  Jhon3     3  Doe3

如何运行 python sqldf 模块里面的静态函数？

How to run python sqldf module inside static function?

python

pandas

dataframe

sqldf