Feature: Add set/zip function to contexts

.changes/unreleased/Features-20220423-231756.yaml

@@ -0,0 +1,7 @@
+kind: Features
+body: Add set and zip function to contexts
+time: 2022-04-23T23:17:56.851793+12:00
+custom:
+ Author: jeremyyeo
+ Issue: "2345"
+ PR: "5107"

core/dbt/context/base.py

@@ -1,15 +1,16 @@
 import json
 import os
-from typing import Any, Dict, NoReturn, Optional, Mapping
+from typing import Any, Dict, NoReturn, Optional, Mapping, Iterable, Set
 
 from dbt import flags
 from dbt import tracking
 from dbt.clients.jinja import get_rendered
 from dbt.clients.yaml_helper import yaml, safe_load, SafeLoader, Loader, Dumper # noqa: F401
 from dbt.contracts.graph.compiled import CompiledResource
 from dbt.exceptions import (
- raise_compiler_error,
+ CompilationException,
  MacroReturn,
+ raise_compiler_error,
  raise_parsing_error,
  disallow_secret_env_var,
 )
@@ -482,6 +483,94 @@ def toyaml(
  except (ValueError, yaml.YAMLError):
  return default
 
+ @contextmember("set")
+ @staticmethod
+ def _set(value: Iterable[Any], default: Any = None) -> Optional[Set[Any]]:
+ """The `set` context method can be used to convert any iterable
+ to a sequence of iterable elements that are unique (a set).
+
+ :param value: The iterable
+ :param default: A default value to return if the `value` argument
+ is not an iterable
+
+ Usage:
+ {% set my_list = [1, 2, 2, 3] %}
+ {% set my_set = set(my_list) %}
+ {% do log(my_set) %} {# {1, 2, 3} #}
+ """
+ try:
+ return set(value)
+ except TypeError:
+ return default
+
+ @contextmember
+ @staticmethod
+ def try_set(value: Iterable[Any]) -> Set[Any]:
+ """The `try_set` context method can be used to convert any iterable
+ to a sequence of iterable elements that are unique (a set). The
+ difference to the `set` context method is that the `try_set` method
+ will raise an exception on a TypeError.
+
+ :param value: The iterable
+ :param default: A default value to return if the `value` argument
+ is not an iterable
+
+ Usage:
+ {% set my_list = [1, 2, 2, 3] %}
+ {% set my_set = try_set(my_list) %}
+ {% do log(my_set) %} {# {1, 2, 3} #}
+ """
+ try:
+ return set(value)
+ except TypeError as e:
+ raise CompilationException(e)
+
+ @contextmember("zip")
+ @staticmethod
+ def _zip(*args: Iterable[Any], default: Any = None) -> Optional[Iterable[Any]]:
+ """The `try_zip` context method can be used to used to return
+ an iterator of tuples, where the i-th tuple contains the i-th
+ element from each of the argument iterables.
+
+ :param *args: Any number of iterables
+ :param default: A default value to return if `*args` is not
+ iterable
+
+ Usage:
+ {% set my_list_a = [1, 2] %}
+ {% set my_list_b = ['alice', 'bob'] %}
+ {% set my_zip = zip(my_list_a, my_list_b) | list %}
+ {% do log(my_set) %} {# [(1, 'alice'), (2, 'bob')] #}
+ """
+ try:
+ return zip(*args)
+ except TypeError:
+ return default
+
+ @contextmember
+ @staticmethod
+ def try_zip(*args: Iterable[Any]) -> Iterable[Any]:
+ """The `try_zip` context method can be used to used to return
+ an iterator of tuples, where the i-th tuple contains the i-th
+ element from each of the argument iterables. The difference to the
+ `zip` context method is that the `try_zip` method will raise an
+ exception on a TypeError.
+
+ :param *args: Any number of iterables
+ :param default: A default value to return if `*args` is not
+ iterable
+
+ Usage:
+ {% set my_list_a = [1, 2] %}
+ {% set my_list_b = ['alice', 'bob'] %}
+ {% set my_zip = try_zip(my_list_a, my_list_b) | list %}
+ {% do log(my_set) %} {# [(1, 'alice'), (2, 'bob')] #}
+ """
+ try:
+ return zip(*args)
+ except TypeError as e:
+ raise CompilationException(e)
+
  @contextmember
  @staticmethod
  def log(msg: str, info: bool = False) -> str: