Jinja reserved keywords

Jinja, like many programming and templating languages, has a set of reserved keywords that can't be used as identifiers for variables, functions, or other custom elements within your templates. These keywords are integral to Jinja's syntax and functionality.

• Always prefix your own variables and function names to avoid collision with these reserved words.

• Use these words in the appropriate context to ensure readability and maintainability. ​

List of reserved keywords

Control structures

• if, elif, else: Conditional statements

• for: Looping through sequences

• while: Loop based on a condition

• try, except, finally: Exception handling

• with: Context management ​

Variables and data types

• True, False: Boolean values

• None: Represents null value

• del: Deletes a variable ​

Functions and definitions

• def: Function definition

• return: Returns a value from a function

• yield: Produces a generator

• lambda: Anonymous function

• class: Defines a class ​

Operators and keywords

• and, or, not: Logical operators

• in, is: Comparison operators

• raise: Raise an exception

• assert: Assertion statement

• break, continue: Loop control

• pass: Null operation

• global, nonlocal: Scope specifiers ​

Built-in methods

• split: Splits a string into a list

• items: Returns a list of dictionary's key-value tuple pairs

• replace: Replaces a string with another string

• get: Retrieves the value of a dictionary key

• result, results: Used in Rewst to store outputs. Note that these are not built-in methods, they're used in Rewst as variable named to store outputs and should not cause issues. ​

Imports and modules

• import: Importing modules

• from: Specifies what attributes to import from a module ​

Common error: JSON serialization issue

Error:

​ JSON cannot serialize 'builtin_function_or_method': <built-in method items of dict object at 0x7f618cb407c0> ​

Solution:

​ Ensure that you're not inadvertently referencing a built-in method like items as an object when you actually intend to use its output. Execute the method first before attempting to serialize it to JSON. ​

Example:

​ If the output of an API call stores all the items in a key named items, reference it like this: ​

{{CTX.customers.data["items"]}}

​ This ensures that you're referencing the actual data rather than the built-in items method, thus avoiding the serialization issue.