WebOct 28, 2024 · yes exactly - see the docs for dask.dataframe Categoricals. Calling .categorize triggers a compute of the full pipeline in order to get the set of categories. what's more - this doesn't result in persisting or computing the dataframe, so any subsequent operations would need to redo the previous steps once a compute was triggered. to … WebThese data types can be larger than your memory, Dask will run computations on your data parallel (y) in Blocked manner. Blocked in the sense that they perform large …
python - Why is the compute() method slow for Dask dataframes …
WebJan 26, 2024 · dask - compute very slow when processing large array - Stack Overflow compute very slow when processing large array Ask Question Asked 5 years, 1 month ago Modified 5 years, 1 month ago Viewed 2k times 4 I'm trying to read in a 220 GB csv file with dask. Each line of this file has a name, a unique id, and the id of its parent. WebNov 6, 2024 · Keep in mind that dask operations are lazy by default and are only triggered when needed. So in general, be careful with statements like "I expect line N to be slow and line N + 1 to be fast, but in practice N is fast and N + 1 is slow." - you need to be really sure that the observed execution time is being attributed correctly. fork truck charging station requirements
python - Why does Dask read parquet file in a lot slower than …
WebJan 23, 2024 · In this example from dask.distributed import Client from dask import delayed client = Client () def f (*args): return args result = [delayed (f) (x) for x in range (1000)] x1 = client.compute (result) x2 = client.persist (result) WebNov 12, 2024 · 1 Answer Sorted by: 1 My first guess is that Pandas saves Parquet datasets into a single row group, which won't allow a system like Dask to parallelize. That doesn't explain why it's slower, but it does explain why it isn't faster. For further information I would recommend profiling. You may be interested in this document: WebBest Practices Call delayed on the function, not the result. Dask delayed operates on functions like dask.delayed (f) (x, y), not on... Compute on lots of computation at once. … fork truck charging station