json2csv

Json -> CSV conversion utility

json2csv is able to convert arbitrary newline-delimited JSON (.ndjson) into a valid CSV. Currently, json2csv supports newline-delimited JSON only.

Build json2csv

You need to install Stack

then just execute stack build

Usage

json2csv in.ndjson out.csv +RTS -N

Examples

nested arrays in single document

JSON input:

{"a": [{"b": "b1", "c": [1, 2]},{"b": "b2", "c": [3, 4]}], "d": [10, 20]}

CSV output:

a.$.b	a.$.c.$	d.$
b1	1.0	10.0
b1	1.0	20.0
b1	2.0	10.0
b1	2.0	20.0
b2	3.0	10.0
b2	3.0	20.0
b2	4.0	10.0
b2	4.0	20.0

various types of inner values

JSON input:

{"a": "field a0","b": [{"value": "field b2"}, {"value": "field b xxx"}],"c": [{"value": "field c0"}, {"value": "field c xxx"}]}
{"a": "field a1","b": [{"value": "field b1"}],"c": [{"value": "field c1"}]}
{"a": "field a2","b": [{"value": "field b2"}, {"value": "field b xxx"}],"c": {"value": "field c2"}, "d": 42}

CSV output:

a	b.$.value	c.$.value	d	c.value
field a0	field b2	field c0
field a0	field b2	field c xxx
field a0	field b xxx	field c0
field a0	field b xxx	field c xxx
field a1	field b1	field c1
field a2	field b2		42.0	field c2
field a2	field b xxx		42.0	field c2

flattening

If You don't need to know, which values came from arrays, You can use -f (--flatten)

For the same JSON input it will give the following output:

c.value	a	d	b.value
field c0	field a0		field b2
field c0	field a0		field b xxx
field c xxx	field a0		field b2
field c xxx	field a0		field b xxx
field c1	field a1		field b1
field c2	field a2	42.0	field b2
field c2	field a2	42.0	field b xxx

intersection

You can extract only common fields from all lines with -i (--intersect)

For the same JSON input it will give the following output:

a	b.$.value
field a0	field b2
field a0	field b xxx
field a1	field b1
field a2	field b2
field a2	field b xxx