validators.py 文件源码

def pngValidator(path=None, data=None, fileObj=None):
    """
    Version 3+.

    This checks the signature of the image data.
    """
    assert path is not None or data is not None or fileObj is not None
    if path is not None:
        with open(path, "rb") as f:
            signature = f.read(8)
    elif data is not None:
        signature = data[:8]
    elif fileObj is not None:
        pos = fileObj.tell()
        signature = fileObj.read(8)
        fileObj.seek(pos)
    if signature != pngSignature:
        return False, "Image does not begin with the PNG signature."
    return True, None

# -------------------
# layercontents.plist
# -------------------