# DataFrames, best way to import from JSON format file

**URL:** <https://discourse.julialang.org/t/dataframes-best-way-to-import-from-json-format-file/29946>\
**Category:** Data\
**Created:** [October 15, 2019, 2:43pm UTC](https://discourse.julialang.org/t/dataframes-best-way-to-import-from-json-format-file/29946 "2019-10-15T14:43:18Z")\
**Posts on this page:** 1\
**Showing post:** 5

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**Author:** ![quinnj](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/quinnj/32/11_2.png) [@quinnj](https://discourse.julialang.org/u/quinnj)\
**Post date:** [October 15, 2019, 10:08pm UTC](https://discourse.julialang.org/t/dataframes-best-way-to-import-from-json-format-file/29946/5 "2019-10-15T22:08:04Z")

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Sure, here’s a quick history:

- JSON.jl has been around the longest; takes a very simple, straightforward approach to json parsing/writing, nothing fancy or custom for native Julia objects
- JSON2.jl was started w/ an idea to use generated functions for custom Julia types to generate specialized JSON parsing/writing code that could be much faster than JSON.jl; it was an experiment that worked fairly well, but can incur expensive compilation costs for complex/highly nested objects
- JSON3.jl is a successor of JSON2.jl that took some similar ideas (support for custom object serialization/deserialization), but aims to fix the compilation cost issue by being smarter, and also provides a hybrid lazy parsing approach for generic objects/arrays that is faster than any other solution

I’ll probably deprecate JSON2 at some point, since JSON3.jl is really more of a “breaking release” version of it; there’s also been talk/interest of eventually merging JSON.jl and JSON3.jl, but I’m in favor of letting JSON3.jl bake for a while longer before doing so.

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