实现图像处理管道的Python函数。

Question

我编写了以下函数来处理图像。现在我不确定它是奏鸣曲还是被认为是通心粉代码。我知道扁平比嵌套好，但我看不出有什么方法可以绕过它。

如果" if“语句仅解析为true/false，那么我可以很容易地应用列表理解，但是每个步骤都取决于前面步骤的输出，所以我不认为我可以使用迭代工具。

def get_image(width, height, collection_sku, order_id, name, handle):
    """image processing pipeline"""

    # Check-1 image exception should be checked before proceeding further
    # covers both images in exception(currently bookshelves) list and also personal true doors
    #   1. bookshelves need to be cropped
    #   2. personal images needs to be added in the required size
    if helpers.image_exception(collection_sku):

        # Step-1 Find image folder
        directory_sizes = helpers.find_directory(width, height)

        if directory_sizes is not None:
            # Step-2 Find the image from the given folder.
            key = helpers.find_image(directory_sizes, collection_sku)

            if key is not None:

                requires_resize = helpers.should_resize(width, height)
                requires_flip = helpers.should_flip(handle) and not helpers.flip_exception(collection_sku)

                # Check-2 check whether image requires resizing or flipping
                if requires_resize or requires_flip:

                    # Step-3 Create local directory to store temporary images
                    location, is_created = helpers.local_directory(
                        order_id)

                    if is_created:
                        # Step-4 Download image
                        image = helpers.download_image(key, location, name)

                        if image is not None:
                            width_px = helpers.cm_to_pixel(width)
                            height_px = helpers.cm_to_pixel(height)
                            image_modified = False

                            # Step-5.1 Resize image
                            if requires_resize:
                                helpers.resize_image(image, width_px, height_px)
                                image_modified = True

                            # Step-5.2 Flip image
                            if requires_flip:
                                helpers.flip_image(image)
                                image_modified = True

                            # Step-6 Upload image
                            if image_modified:
                                helpers.upload_image(image, key)

                    # Step-3 No local dir created
                    # Step-4 Can't download image
                    # Step-5.1 Can't resize image
                    # Step-5.2 Can't flip image
                    # Step-6 Can't upload image
                    return None

                # Check-2 if no image processing required then copy image over
                helpers.copy_image(key, target=None) # TODO
                return True

    # raise exception in sub job
    #   Check-1 if image door image cannot be processed
    #   Step-1 if directory not available
    #   Step-2 if image not available

    return None

Answer 1

正如莱因德林所提到的，您可以通过反转if-语句来降低代码的一些复杂性。虽然我无法测试这一点，因为我没有完整的代码，但下面是如何实现的：

def get_image(width, height, collection_sku, order_id, name, handle):
    """image processing pipeline"""

    # Check-1 image exception should be checked before proceeding further
    # covers both images in exception(currently bookshelves) list and also personal true doors
    #   1. bookshelves need to be cropped
    #   2. personal TD images needs to be added in the required size when it's submitted by the user.
    if not helpers.image_exception(collection_sku):
        return None

    # Step-1 Find image folder
    directory_sizes = helpers.find_directory(width, height)

    if directory_sizes is None:
        return None

    # Step-2 Find the image from the given folder.
    key = helpers.find_image(directory_sizes, collection_sku)

    if key is None:
        return None

    requires_resize = helpers.should_resize(width, height)
    requires_flip = helpers.should_flip(handle) and not helpers.flip_exception(collection_sku)

    # Check-2 check whether image requires resizing or flipping
    if requires_resize or requires_flip:

        # Step-3 Create local directory to store temporary images
        location, is_created = helpers.local_directory(
            order_id)

        if not is_created:
            return None

        # Step-4 Download image
        image = helpers.download_image(key, location, name)

        if image is not None:
            width_px = helpers.cm_to_pixel(width)
            height_px = helpers.cm_to_pixel(height)
            image_modified = False

            # Step-5.1 Resize image
            if requires_resize:
                helpers.resize_image(image, width_px, height_px)
                image_modified = True

            # Step-5.2 Flip image
            if requires_flip:
                helpers.flip_image(image)
                image_modified = True

            # Step-6 Upload image
            if image_modified:
                helpers.upload_image(image, key)

        # Step-3 No local dir created
        # Step-4 Can't download image
        # Step-5.1 Can't resize image
        # Step-5.2 Can't flip image
        # Step-6 Can't upload image

    # Check-2 if no image processing required then copy image over
    helpers.copy_image(key, target = None) # TODO
    return True

    # raise exception in sub job
    #   Check-1 if image door image cannot be processed
    #   Step-1 if directory not available
    #   Step-2 if image not available

对我来说，这大大提高了可读性--在此之前，很难弄清楚if语句是做什么的(特别是在它们的末尾有代码片段)。但是，您的评论在描述过程的过程中是有用的。

我相信它可以被更多地压平，但这应该证明了它的想法。希望这能有所帮助！