How to append new record of everyday to a new row in pandas dataframe?-CodePudding

I have a dataframe which contains an aggregated value till today. My datastream will update everyday so that I want to monitoring the change of each day. How can I append each newday's data to the dataframe?

The format will be like this,

   Date      Agg_Value
2022-12-07      0.43
2022-12-08      0.44
2022-12-09      0.41
 ...            ...

CodePudding user response：

You want to use pandas.concat to bring together 2 dataframes:

import pandas as pd

s1 = pd.Series(['a', 'b'])
s2 = pd.Series(['c', 'd'])
print(pd.concat([s1, s2]))

CodePudding user response：

Assuming that you always have yesterday's dataframe available, you can simply execute a script that runs everyday to get today's date and concatenate the result.

# Assuming you have todays value
today_value = 42

# Get today's date
from datetime import date
today = date.today()

# Create a new dataframe with today's value
df1 = pd.DataFrame(
    {
        'Date':[str(today)],
        'Agg_value':[today_value]
    }
)

# Update df by concatenating today's data
df = pd.concat([df, df1], axis=0)