Method: Polars::StringExpr#json_path_match

Defined in:
lib/polars/string_expr.rb

#json_path_match(json_path) ⇒ Expr

Extract the first match of json string with provided JSONPath expression.

Throw errors if encounter invalid json strings. All return value will be casted to Utf8 regardless of the original value.

Documentation on JSONPath standard can be found here.

Examples:

df = Polars::DataFrame.new(
  {"json_val" => ['{"a":"1"}', nil, '{"a":2}', '{"a":2.1}', '{"a":true}']}
)
df.select(Polars.col("json_val").str.json_path_match("$.a"))
# =>
# shape: (5, 1)
# ┌──────────┐
# │ json_val │
# │ ---      │
# │ str      │
# ╞══════════╡
# │ 1        │
# │ null     │
# │ 2        │
# │ 2.1      │
# │ true     │
# └──────────┘

Parameters:

  • json_path (String) —

    A valid JSON path query string.

Returns:



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# File 'lib/polars/string_expr.rb', line 1001

def json_path_match(json_path)
  json_path = Utils.parse_into_expression(json_path, str_as_lit: true)
  Utils.wrap_expr(_rbexpr.str_json_path_match(json_path))
end