Hi everyone,
I've been using AmiBroker for some time and typically import price data using the ASCII import function for my analysis.
Recently, I started using an automated data download process using a Python script that saves EOD data into CSV files, for eg: stockname.csv, 'stockname2.csv' etc. Each day the script updates the same CSV file with the latest EOD data, appending new rows.
However, when I import this data into AmiBroker daily using the standard ASCII import, it re-imports both the old and new data, this significantly increases the import time. (The files contain EOD data from 2000s)
My question is, is there a way to import only the latest data from these CSV files (eg: stockname1.csv, stockname2.csv, etc.) while ignoring data that has already been imported into Ami?
It appears you are creating a local copy of the data by appending quotes to 1 CSV file for each "stock name".
In that case, when you download data, write/append each days stock data to one temp file, then use that file to import in AB. Then delete it.
Dont use your main files.
You will be writing/appending the same data to main file and temp file.
Once import is done, delete the temp file.
There is no way to change AB ASCII Import mechanism, it is very complex, and by design it will have to process all quotes that are supplied to its import file.
If your stock_files dont have a single import format file, then you can batch your imports according to import.
You can use AB COM/OLE to import, and you can check out AB Batch, there is import feature in it too.