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import re |
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from io import BytesIO |
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import base64 |
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from typing import Union |
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from .typing import ImageType |
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try: |
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from PIL import Image |
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except ImportError: |
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Image = None |
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from .errors import MissingRequirementsError |
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ALLOWED_EXTENSIONS = {'png', 'jpg', 'jpeg', 'gif', 'webp', 'svg'} |
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def is_allowed_extension(filename: str) -> bool: |
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""" |
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Checks if the given filename has an allowed extension. |
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""" |
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return '.' in filename and \ |
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filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS |
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def is_data_uri_an_image(data_uri: str) -> bool: |
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""" |
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Checks if the given data URI represents an image. |
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""" |
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if not re.match(r'data:image/(\w+);base64,', data_uri): |
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raise ValueError("Invalid data URI image.") |
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image_format = re.match(r'data:image/(\w+);base64,', data_uri).group(1).lower() |
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if image_format not in ALLOWED_EXTENSIONS and image_format != "svg+xml": |
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raise ValueError("Invalid image format (from MIME type).") |
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return True |
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def extract_data_uri(data_uri: str) -> bytes: |
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""" |
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Extracts the binary data from the given data URI. |
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""" |
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data = data_uri.split(",")[1] |
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return base64.b64decode(data) |
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def to_data_uri(image: str) -> str: |
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""" |
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Validates and returns the data URI for an image. |
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""" |
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is_data_uri_an_image(image) |
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return image |
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def to_image(image: str) -> ImageType: |
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""" |
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Converts a base64-encoded image to bytes. |
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""" |
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if Image is None: |
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raise MissingRequirementsError('Install "pillow" package for image processing.') |
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is_data_uri_an_image(image) |
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return extract_data_uri(image) |
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class MissingRequirementsError(Exception): |
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pass |
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class ImageResponse: |
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def __init__(self, url: str, alt: str): |
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self.url = url |
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self.alt = alt |
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