Good ole’ string slicing. That’s one thing that never changes in Data Engineering, working with strings. You would think we would all get to row up some day and do the complicated stuff, but apparently you can’t outrun your past. I blame this mostly on the data and old schools companies. Plain text and flat files are still incredibly popular and common for storing and exporting data between systems. Hence string work comes upon us all like some terrible overload. The one you should fear the most is fixed width delimited files. I ran into a problem recently where PySpark was surprisingly terrible at processing fixed with delimited files and “string slicing.” It got me wondering … is it me or you?

With parquet taking over the big data world, as it should, and csv files being that third wheel that just will never go away…. it’s becoming more and more common to see the repetitive task of converting csv files into parquets. There are lots of reasons to do this, compression, fast reads, integrations with tools like Spark, better schema handling, and the list goes on. Today I want to see how many ways I can figure out how to simple convert an existing csv file to a parquet with Python, Scala, and whatever else there is out there. And how simple and fast each option is. Let’s do it!