Pretty-print GeoJSON in a slightly more compact way by putting coordinates on one line.

gql.py

#!/usr/bin/env python3
"""Pretty-print GeoJSON in a slightly more compact way by putting coordinates on one line.

Compare:

    [
        [
            37.23423,
            79.23423
        ],
        [
            37.24434,
            80.01234
        ]
    ]

vs.

    [
        [ 37.23423, 79.23423 ],
        [ 37.24434, 80.01234 ]
    ]
"""

import json
import sys


# See https://stackoverflow.com/a/26512016/388951
class CompactJSONEncoder(json.JSONEncoder):
    def __init__(self, *args, **kwargs):
        super(CompactJSONEncoder, self).__init__(*args, **kwargs)
        self.current_indent = 0
        self.current_indent_str = ''

    def encode(self, o):
        # Special Processing for lists
        if isinstance(o, (list, tuple)):
            primitives_only = True
            for item in o:
                if isinstance(item, (list, tuple, dict)):
                    primitives_only = False
                    break
            output = []
            if primitives_only:
                for item in o:
                    output.append(json.dumps(item))
                return '[ ' + ', '.join(output) + ' ]'
            else:
                self.current_indent += self.indent
                self.current_indent_str = ''.join([' ' for x in range(self.current_indent)])
                for item in o:
                    output.append(self.current_indent_str + self.encode(item))
                self.current_indent -= self.indent
                self.current_indent_str = ''.join([' ' for x in range(self.current_indent)])
                return '[\n' + ',\n'.join(output) + '\n' + self.current_indent_str + ']'
        elif isinstance(o, dict):
            output = []
            self.current_indent += self.indent
            self.current_indent_str = ''.join([' ' for x in range(self.current_indent)])
            for key, value in o.items():
                output.append(
                    self.current_indent_str + json.dumps(key) + ': ' + self.encode(value)
                )
            self.current_indent -= self.indent
            self.current_indent_str = ''.join([' ' for x in range(self.current_indent)])
            return '{\n' + ',\n'.join(output) + '\n' + self.current_indent_str + '}'
        else:
            return json.dumps(o)


if __name__ == '__main__':
    if len(sys.argv) == 1:
        geojson = json.load(sys.stdin)
    else:
        with open(sys.argv[1]) as f:
            geojson = json.load(f)

    print(CompactJSONEncoder(indent=2).encode(geojson))