initial commit

get-json-key.py

@@ -0,0 +1,30 @@
+#!/usr/bin/env python3
+
+import fileinput, sys, json, functools
+from typing import Union, List
+
+JsonKey = Union[str, int]
+
+def try_int(x: str) -> JsonKey:
+    try:
+        return int(x)
+    except:
+        return x
+
+def main(indices: List[str]) -> None:
+    for line in fileinput.input(files=('-',)):
+        data = json.loads(line)
+        try:
+            val = functools.reduce(lambda x, i: x[try_int(i)], indices, data)
+        except Exception as e:
+            print('indexing json data failed with keys {}: {}\n'.format(' > '.join(indices), e), file=sys.stderr)
+            raise e
+        print(val)
+
+if __name__ == '__main__':
+    if len(sys.argv) < 2:
+        print('USAGE: ./get-json-key.py [KEY].. < json-input', file=sys.stderr)
+        sys.exit(1)
+    main(sys.argv[1:])
+
+