根据条件从 dataframe 创建列表列表

Question

im working with some financial data and I want to create a list of lists while iterating through a df and a certain condition is met

eg: df

        25 Day   250 Day
Date                          
2001-12-07  1.4  1.5
2001-12-10  1.6  1.7
2001-12-11  1.8  1.2
2001-12-12  1.4  1.5
2001-12-13  1.4  1.6

I want to loop through the rows and make a list when 25 Day < 250 Day. This condition is intermittent and may last for a couple rows at a time before breaking. I want to eventually use this data to plot something on a graph.

In the example above I should get the following: [[2001-12-07, 2001-12-10], [2001-12-12,2001-12-13]]

Im currently using the following to iterate through the rows and get a list of all of the values, but don't know how I would put all of the continuous values inside separate lists

def get_Date():
    global date_Buy
    x = []
    date_Buy = [[x]]
    for i, value in master_Data.iterrows():
        if value['25 Day'] < value['250 Day']:
            x.append(i)
        else:
            continue
            date_Buy.append(x)
get_Date()

Essentially I would like to start a new list each time the continue is triggered

Answer 1

Do you want something like this?

import pandas as pd

df = pd.DataFrame({'Date': ['2018-01-02', '2019-03-31', '2019-03-31', '2018-01-02', '2018-01-02', '2019-04-31',
                            '2018-01-02'],
                   'Day_25': [1, 920, 920, 920, 921, 921, 921],
                   'Day_250': [100, 2, 3000, 4, 600, 7, 8]})

index_greater=df[df.Day_25 > df.Day_250].index

Answer 2

You can filter using query then convert each row to list using agg :

lst = df.query("Day_25 > Day_250").reset_index().agg(list, 1).tolist()

print(lst)

[['2019-03-31', 920, 2],
 ['2018-01-02', 920, 4],
 ['2018-01-02', 921, 600],
 ['2019-04-31', 921, 7],
 ['2018-01-02', 921, 8]]