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40 lines
1.5 KiB
Python
40 lines
1.5 KiB
Python
import re
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REGEX = re.compile(r"\{\{([a-zA-Z_][a-zA-Z0-9_]{1,29}|#histories#|#query#|#context#)\}\}")
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class PromptTemplateParser:
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"""
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Rules:
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1. Template variables must be enclosed in `{{}}`.
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2. The template variable Key can only be: letters + numbers + underscore, with a maximum length of 16 characters,
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and can only start with letters and underscores.
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3. The template variable Key cannot contain new lines or spaces, and must comply with rule 2.
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4. In addition to the above, 3 types of special template variable Keys are accepted:
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`{{#histories#}}` `{{#query#}}` `{{#context#}}`. No other `{{##}}` template variables are allowed.
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"""
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def __init__(self, template: str):
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self.template = template
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self.variable_keys = self.extract()
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def extract(self) -> list:
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# Regular expression to match the template rules
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return re.findall(REGEX, self.template)
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def format(self, inputs: dict, remove_template_variables: bool = True) -> str:
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def replacer(match):
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key = match.group(1)
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value = inputs.get(key, match.group(0)) # return original matched string if key not found
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if remove_template_variables:
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return PromptTemplateParser.remove_template_variables(value)
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return value
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return re.sub(REGEX, replacer, self.template)
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@classmethod
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def remove_template_variables(cls, text: str):
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return re.sub(REGEX, r'{\1}', text)
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