json_get has one class, JsonGet, with one method, match().
JsonGet(‘{“string”: “formatted in JSON”}’)
JsonGet(value=[“Any”, “JSON-like”, “data”])
Match by passing a data structure into ``match() - there's no separate DSL. If the data structure matches, a JsonMatch object will be returned, containing the matched data; if the match fails, None will be returned.
Wildcards for dictionary keys:
Any matches any data. If used as a value in a dictionary, the key must exist.Maybe matches any data, and if a key is missing, that key will be added with value None.None as a value in a dictionary requires that the key not be present.Any is also a wildcard for list patterns, and for matching any data object.
Any and Maybe return shallow copies of the data they match, so the original structure can be modified.
def match(self, pattern, callback=None, no_match=None)
In addition, a 1-argument function passed as callback will be called with a successful match, and a 0-argument function passed as no_match will be called if the match fails.
from json_get import JsonGet, Any, Maybe # Any is typing.Any
j = JsonGet('{"a": 1, "b": [7, 8, {"nested": 42}]})
print(j.match({"a": Any}).a) # prints 1
print(j.match({"a": Any}).b) # Error - the returned object doesn't have a field `b`
print(j.match({"b": [{"nested": Any}])).b.nested # prints 42
print(j.match({"b": [7])).b # prints [7]
print(j.match({"b": [Any])).b # prints [7, 8, {"nested": 42}]
Maybe and None are only meaningful as dictionary values. Keys must match exactly, and must be valid Python object-member names.
A list in a pattern must contain exactly one item. The corresponding data must be a list. Each element of that list that matches the pattern will be added to the returned list. If nothing matches, the returned value is [] rather than None. To match an entire list, use [Any].