What are recommended ways\tools for processing large data from Excel Files? A Very Happy New Year! I'm currently working on an analytics project with large volumes of data stored in excel files (about 50GB in 1000 files). The files use a custom formatting to store date-time data to the millisecond. The processing also has to be efficient in view of the large data volume. What is the recommended methodology and tool to handle this? 

I've seen others convert excel to CSV, and then confining their analysis to the CSV itself. Is this method advantageous in the sense that CSV is faster to read in, and can be processed by a larger toolset? Is there any powerful tool\library that can do batch conversion, and even extract custom formatting data? 

Thanks and Regards
pandas loads a csv upto 10x faster than excel. So, if you can, please convert these files to csv, which ever ones that are being loaded several times.

I have been using cython, which seems to speedup read functions and processing. Please follow this link for more details. It says, that using cython speeds up the processing 10x.

Suggestion: If you can, I would recommend to store data in database and use an orm like django/peewee for the data processing. 

Please lemme know if you have any other queries.