91 lines
3.1 KiB
Python
91 lines
3.1 KiB
Python
from __future__ import annotations
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import base64
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from io import BytesIO
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from typing import Any, Tuple
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import webcolors
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from PIL import Image
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from werkzeug.datastructures import FileStorage
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def is_integer(contender: Any) -> bool:
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"""
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Determine if a string (or other object type that can be converted automatically) represents an integer.
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Thanks to https://note.nkmk.me/en/python-check-int-float/.
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:param contender: object to test
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:return: true if it's an integer
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"""
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try:
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float(contender)
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except ValueError:
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return False
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else:
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return float(contender).is_integer()
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def thumbnail_uploaded_image(file: FileStorage, max_size: Tuple[int, int] = (256, 256)) -> bytes:
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"""
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Process an uploaded image file into a resized image of a specific size.
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:param file: An uploaded image file.
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:param max_size: A tuple containing the maximum width and height for the thumbnail image. Default is (256, 256).
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:return: The byte data of the thumbnail image.
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"""
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if file.filename is None:
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raise ValueError("No file was uploaded")
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img = Image.open(file)
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img.thumbnail(max_size)
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byte_arr = BytesIO()
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img.save(byte_arr, format='PNG' if file.filename.lower().endswith('.png') else 'JPEG')
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return byte_arr.getvalue()
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def create_data_uri(bytes_data: bytes, file_extension: str) -> str:
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"""
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Create a data URI from binary data and a file extension.
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:param bytes_data: The binary data of an image.
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:param file_extension: The file extension of the image.
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:return: A data URI representing the image.
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"""
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# base64 encode
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encoded = base64.b64encode(bytes_data).decode('ascii')
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# create data URI
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data_uri = "data:image/{};base64,{}".format('jpeg' if file_extension == 'jpg' else file_extension, encoded)
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return data_uri
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def normalize_color(color: str) -> str:
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"""
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Normalize a string representing a color to its hexadecimal representation.
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This function accepts a string representing a color in one of the following formats:
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- A CSS color name, such as 'red', 'green', or 'blue'.
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- A 6-digit hexadecimal color code, such as '#FF0000' for red.
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- A 3-digit hexadecimal color code, such as '#F00' for red.
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The function returns a string with the color in 6-digit or 3-digit hexadecimal format,
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with lowercase letters. If the color is given as a CSS color name, the function
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returns its equivalent 6-digit hexadecimal format.
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:param color: A string representing a color.
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:return: The color in 6-digit or 3-digit hexadecimal format.
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:raises: ValueError: If the input string does not represent a valid color in any of the accepted formats.
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"""
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try:
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return webcolors.name_to_hex(color) # type: ignore[no-any-return]
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except ValueError:
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pass
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if color.startswith('#'):
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color = color[1:].lower()
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if len(color) in [3, 6]:
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try:
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_ = int(color, 16)
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return f"#{color}"
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except ValueError:
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pass
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raise ValueError(f"color must be a valid HTML color, got: {repr(color)}")
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