迁移至 Python 客户端库 v0.25.1

Python 客户端库 v0.25.1 针对以前的客户端库设计进行了一些重大更改。这些更改可以总结如下：

  • 整合模块合以减少类型

  • 将无类型参数替换为强类型的类和枚举

本主题详细介绍您需要针对 Cloud Vision API 客户端库对 Python 代码进行什么更改，才能使用 v0.25.1 Python 客户端库。

运行旧版客户端库

您无需将 Python 客户端库升级到 v0.25.1。如果您想要继续使用先前版本的 Python 客户端库，且不想迁移您的代码，那么您应指定您的应用所使用的 Python 客户端库版本。要指定特定的库版本，请按如下所示修改 requirements.txt 文件：

google-cloud-vision==0.25

已移除的模块

Python 客户端库 v0.25.1 软件包中已移除以下模块。

  • google.cloud.vision.annotations

  • google.cloud.vision.batch

  • google.cloud.vision.client

  • google.cloud.vision.color

  • google.cloud.vision.crop_hint

  • google.cloud.vision.entity

  • google.cloud.vision.face

  • google.cloud.vision.feature

  • google.cloud.vision.geometry

  • google.cloud.vision.image

  • google.cloud.vision.likelihood

  • google.cloud.vision.safe_search

  • google.cloud.vision.text

  • google.cloud.vision.web

所需的代码更改

导入

添加新的 google.cloud.vision.types 模块以访问 Python 客户端库 v0.25.1 中的新类型。

types 模块包含创建请求所需的新类，例如 types.Image。

from google.cloud import vision

此外，新的 google.cloud.vision.enums 模块包含用于解析和理解 API 响应的枚举，如 enums.Likelihood.UNLIKELY 和 enums.FaceAnnotation.Landmark.Type.LEFT_EYE。

创建客户端

Client 类已替换为 ImageAnnotatorClient 类。请将对 Client 类的引用替换为 ImageAnnotatorClient。

旧版客户端库：

old_client = vision.Client()

Python 客户端库 v0.25.1：

client = vision.ImageAnnotatorClient()

构建表示图片内容的对象

要识别图片内容是来自本地文件、Google Cloud Storage URI 还是网页 URI，请使用新的 Image 类。

构建表示来自本地文件的图片内容的对象

以下示例展示了如何通过新方式表示来自本地文件的图片内容。

旧版客户端库：

with io.open(file_name, 'rb') as image_file:
    content = image_file.read()

image = old_client.image(content=content)

Python 客户端库 v0.25.1：

with open(path, "rb") as image_file:
    content = image_file.read()

image = vision.Image(content=content)

构建表示来自 URI 的图片内容的对象

以下示例展示了表示来自 Google Cloud Storage URI 或网络 URI 的图片内容的新方式。uri 是指 Google Cloud Storage 或网络上的图片文件的 URI。

旧版客户端库：

image = old_client.image(source_uri=uri)

Python 客户端库 v0.25.1：

image = vision.Image()
image.source.image_uri = uri

发出请求并处理响应

在 Python 客户端库 v.0.25.1 中，face_detection 等 API 方法属于 ImageAnnotatorClient 对象，而非 Image 对象。

如下文所述，多种方法返回的值有所不同。

需特别注意，边界框顶点现在存储在 bounding_poly.vertices（而不是 bounds.vertices）中。每个顶点的坐标存储在 vertex.x 和 vertex.y 中（而不是 vertex.x_coordinate 和 vertex.y_coordinate 中）。

边界框更改会影响 face_detection、logo_detection、text_detection、document_text_detection 和 crop_hints。

发出人脸检测请求并处理响应

现在，情绪可能性以枚举的形式返回（存储在 face.surprise_likelihood 而不是 face.emotions.surprise 中）。可能性标签的名称可以通过导入 google.cloud.vision.enums.Likelihood 来恢复。

以前版本的客户端库：

with io.open(file_name, 'rb') as image_file:
    content = image_file.read()

image = old_client.image(content=content)

faces = image.detect_faces()

for face in faces:
    print('anger: {}'.format(face.emotions.anger))
    print('joy: {}'.format(face.emotions.joy))
    print('surprise: {}'.format(face.emotions.surprise))

    vertices = (['({},{})'.format(bound.x_coordinate, bound.y_coordinate)
                for bound in face.bounds.vertices])

    print('face bounds: {}'.format(','.join(vertices)))

Python 客户端库 v0.25.1：

with open(path, "rb") as image_file:
    content = image_file.read()

image = vision.Image(content=content)

response = client.face_detection(image=image)
faces = response.face_annotations

# Names of likelihood from google.cloud.vision.enums
likelihood_name = (
    "UNKNOWN",
    "VERY_UNLIKELY",
    "UNLIKELY",
    "POSSIBLE",
    "LIKELY",
    "VERY_LIKELY",
)
print("Faces:")

for face in faces:
    print(f"anger: {likelihood_name[face.anger_likelihood]}")
    print(f"joy: {likelihood_name[face.joy_likelihood]}")
    print(f"surprise: {likelihood_name[face.surprise_likelihood]}")

    vertices = [
        f"({vertex.x},{vertex.y})" for vertex in face.bounding_poly.vertices
    ]

    print("face bounds: {}".format(",".join(vertices)))

if response.error.message:
    raise Exception(
        "{}\nFor more info on error messages, check: "
        "https://cloud.google.com/apis/design/errors".format(response.error.message)
    )

发出标签检测请求并处理响应

以前版本的客户端库：

with io.open(file_name, 'rb') as image_file:
    content = image_file.read()

image = old_client.image(content=content)

labels = image.detect_labels()

for label in labels:
    print(label.description)

Python 客户端库 v0.25.1：

with open(path, "rb") as image_file:
    content = image_file.read()

image = vision.Image(content=content)

response = client.label_detection(image=image)
labels = response.label_annotations
print("Labels:")

for label in labels:
    print(label.description)

if response.error.message:
    raise Exception(
        "{}\nFor more info on error messages, check: "
        "https://cloud.google.com/apis/design/errors".format(response.error.message)
    )

发出地标检测请求并处理响应

以前版本的客户端库：

地标位置的纬度和经度现在存储在 location.lat_lng.latitude 和 location.lat_lng.longitude（而不是 location.latitude 和 location.longitude）中。

with io.open(file_name, 'rb') as image_file:
    content = image_file.read()

image = old_client.image(content=content)

landmarks = image.detect_landmarks()

for landmark in landmarks:
    print(landmark.description, landmark.score)
    for location in landmark.locations:
        print('Latitude'.format(location.latitude))
        print('Longitude'.format(location.longitude))

Python 客户端库 v0.25.1：

with open(path, "rb") as image_file:
    content = image_file.read()

image = vision.Image(content=content)

response = client.landmark_detection(image=image)
landmarks = response.landmark_annotations
print("Landmarks:")

for landmark in landmarks:
    print(landmark.description)
    for location in landmark.locations:
        lat_lng = location.lat_lng
        print(f"Latitude {lat_lng.latitude}")
        print(f"Longitude {lat_lng.longitude}")

if response.error.message:
    raise Exception(
        "{}\nFor more info on error messages, check: "
        "https://cloud.google.com/apis/design/errors".format(response.error.message)
    )

发出徽标检测请求并处理响应

以前版本的客户端库：

with io.open(file_name, 'rb') as image_file:
    content = image_file.read()

image = old_client.image(content=content)

logos = image.detect_logos()

for logo in logos:
    print(logo.description, logo.score)

Python 客户端库 v0.25.1：

with open(path, "rb") as image_file:
    content = image_file.read()

image = vision.Image(content=content)

response = client.logo_detection(image=image)
logos = response.logo_annotations
print("Logos:")

for logo in logos:
    print(logo.description)

if response.error.message:
    raise Exception(
        "{}\nFor more info on error messages, check: "
        "https://cloud.google.com/apis/design/errors".format(response.error.message)
    )

发出安全搜索检测请求并处理响应

安全搜索可能性现在以枚举的形式返回。可能性标签的名称可以通过导入 google.cloud.vision.enums.Likelihood 来恢复。

以前版本的客户端库：

with io.open(file_name, 'rb') as image_file:
    content = image_file.read()

image = old_client.image(content=content)

safe = image.detect_safe_search()
print('Safe search:')
print('adult: {}'.format(safe.adult))
print('medical: {}'.format(safe.medical))
print('spoofed: {}'.format(safe.spoof))
print('violence: {}'.format(safe.violence))

Python 客户端库 v0.25.1：

with open(path, "rb") as image_file:
    content = image_file.read()

image = vision.Image(content=content)

response = client.safe_search_detection(image=image)
safe = response.safe_search_annotation

# Names of likelihood from google.cloud.vision.enums
likelihood_name = (
    "UNKNOWN",
    "VERY_UNLIKELY",
    "UNLIKELY",
    "POSSIBLE",
    "LIKELY",
    "VERY_LIKELY",
)
print("Safe search:")

print(f"adult: {likelihood_name[safe.adult]}")
print(f"medical: {likelihood_name[safe.medical]}")
print(f"spoofed: {likelihood_name[safe.spoof]}")
print(f"violence: {likelihood_name[safe.violence]}")
print(f"racy: {likelihood_name[safe.racy]}")

if response.error.message:
    raise Exception(
        "{}\nFor more info on error messages, check: "
        "https://cloud.google.com/apis/design/errors".format(response.error.message)
    )

发出文本检测请求并处理响应

以前版本的客户端库：

with io.open(file_name, 'rb') as image_file:
    content = image_file.read()

image = old_client.image(content=content)

texts = image.detect_text()

for text in texts:
    print('\n"{}"'.format(text.description))

    vertices = (['({},{})'.format(bound.x_coordinate, bound.y_coordinate)
                for bound in text.bounds.vertices])

    print('bounds: {}'.format(','.join(vertices)))

Python 客户端库 v0.25.1：

with open(path, "rb") as image_file:
    content = image_file.read()

image = vision.Image(content=content)

response = client.text_detection(image=image)
texts = response.text_annotations
print("Texts:")

for text in texts:
    print(f'\n"{text.description}"')

    vertices = [
        f"({vertex.x},{vertex.y})" for vertex in text.bounding_poly.vertices
    ]

    print("bounds: {}".format(",".join(vertices)))

if response.error.message:
    raise Exception(
        "{}\nFor more info on error messages, check: "
        "https://cloud.google.com/apis/design/errors".format(response.error.message)
    )

发出文档文本检测请求并处理响应

以前版本的客户端库：

with io.open(file_name, 'rb') as image_file:
    content = image_file.read()

image = old_client.image(content=content)

document = image.detect_full_text()

for page in document.pages:
    for block in page.blocks:
        block_words = []
        for paragraph in block.paragraphs:
            block_words.extend(paragraph.words)

        block_symbols = []
        for word in block_words:
            block_symbols.extend(word.symbols)

        block_text = ''
        for symbol in block_symbols:
            block_text = block_text + symbol.text

        print('Block Content: {}'.format(block_text))
        print('Block Bounds:\n {}'.format(block.bounding_box))

Python 客户端库 v0.25.1：

with open(path, "rb") as image_file:
    content = image_file.read()

image = vision.Image(content=content)

response = client.document_text_detection(image=image)

for page in response.full_text_annotation.pages:
    for block in page.blocks:
        print(f"\nBlock confidence: {block.confidence}\n")

        for paragraph in block.paragraphs:
            print("Paragraph confidence: {}".format(paragraph.confidence))

            for word in paragraph.words:
                word_text = "".join([symbol.text for symbol in word.symbols])
                print(
                    "Word text: {} (confidence: {})".format(
                        word_text, word.confidence
                    )
                )

                for symbol in word.symbols:
                    print(
                        "\tSymbol: {} (confidence: {})".format(
                            symbol.text, symbol.confidence
                        )
                    )

if response.error.message:
    raise Exception(
        "{}\nFor more info on error messages, check: "
        "https://cloud.google.com/apis/design/errors".format(response.error.message)
    )

发出图片属性请求并处理响应

主色信息现在存储在 props.dominant_colors.colors 而不是 props.colors 中。

以前版本的客户端库：

with io.open(file_name, 'rb') as image_file:
    content = image_file.read()

image = old_client.image(content=content)

props = image.detect_properties()

for color in props.colors:
    print('fraction: {}'.format(color.pixel_fraction))
    print('\tr: {}'.format(color.color.red))
    print('\tg: {}'.format(color.color.green))
    print('\tb: {}'.format(color.color.blue))
    print('\ta: {}'.format(color.color.alpha))

Python 客户端库 v0.25.1：

with open(path, "rb") as image_file:
    content = image_file.read()

image = vision.Image(content=content)

response = client.image_properties(image=image)
props = response.image_properties_annotation
print("Properties:")

for color in props.dominant_colors.colors:
    print(f"fraction: {color.pixel_fraction}")
    print(f"\tr: {color.color.red}")
    print(f"\tg: {color.color.green}")
    print(f"\tb: {color.color.blue}")
    print(f"\ta: {color.color.alpha}")

if response.error.message:
    raise Exception(
        "{}\nFor more info on error messages, check: "
        "https://cloud.google.com/apis/design/errors".format(response.error.message)
    )

发出网络检测请求并处理响应

以前版本的客户端库：

with io.open(file_name, 'rb') as image_file:
    content = image_file.read()

image = old_client.image(content=content)

notes = image.detect_web()

if notes.pages_with_matching_images:
    print('\n{} Pages with matching images retrieved')

    for page in notes.pages_with_matching_images:
        print('Score : {}'.format(page.score))
        print('Url   : {}'.format(page.url))

if notes.full_matching_images:
    print ('\n{} Full Matches found: '.format(
           len(notes.full_matching_images)))

    for image in notes.full_matching_images:
        print('Score:  {}'.format(image.score))
        print('Url  : {}'.format(image.url))

if notes.partial_matching_images:
    print ('\n{} Partial Matches found: '.format(
           len(notes.partial_matching_images)))

    for image in notes.partial_matching_images:
        print('Score: {}'.format(image.score))
        print('Url  : {}'.format(image.url))

if notes.web_entities:
    print ('\n{} Web entities found: '.format(len(notes.web_entities)))

    for entity in notes.web_entities:
        print('Score      : {}'.format(entity.score))
        print('Description: {}'.format(entity.description))

Python 客户端库 v0.25.1：

with open(path, "rb") as image_file:
    content = image_file.read()

image = vision.Image(content=content)

response = client.web_detection(image=image)
annotations = response.web_detection

if annotations.best_guess_labels:
    for label in annotations.best_guess_labels:
        print(f"\nBest guess label: {label.label}")

if annotations.pages_with_matching_images:
    print(
        "\n{} Pages with matching images found:".format(
            len(annotations.pages_with_matching_images)
        )
    )

    for page in annotations.pages_with_matching_images:
        print(f"\n\tPage url   : {page.url}")

        if page.full_matching_images:
            print(
                "\t{} Full Matches found: ".format(len(page.full_matching_images))
            )

            for image in page.full_matching_images:
                print(f"\t\tImage url  : {image.url}")

        if page.partial_matching_images:
            print(
                "\t{} Partial Matches found: ".format(
                    len(page.partial_matching_images)
                )
            )

            for image in page.partial_matching_images:
                print(f"\t\tImage url  : {image.url}")

if annotations.web_entities:
    print("\n{} Web entities found: ".format(len(annotations.web_entities)))

    for entity in annotations.web_entities:
        print(f"\n\tScore      : {entity.score}")
        print(f"\tDescription: {entity.description}")

if annotations.visually_similar_images:
    print(
        "\n{} visually similar images found:\n".format(
            len(annotations.visually_similar_images)
        )
    )

    for image in annotations.visually_similar_images:
        print(f"\tImage url    : {image.url}")

if response.error.message:
    raise Exception(
        "{}\nFor more info on error messages, check: "
        "https://cloud.google.com/apis/design/errors".format(response.error.message)
    )

发出剪裁提示请求并处理响应

以前版本的客户端库：

with io.open(file_name, 'rb') as image_file:
    content = image_file.read()

image = old_client.image(content=content)

hints = image.detect_crop_hints(aspect_ratios=[1.77])

for n, hint in enumerate(hints):
    print('\nCrop Hint: {}'.format(n))

    vertices = (['({},{})'.format(bound.x_coordinate, bound.y_coordinate)
                for bound in hint.bounds.vertices])

    print('bounds: {}'.format(','.join(vertices)))

Python 客户端库 v0.25.1：

with open(path, "rb") as image_file:
    content = image_file.read()
image = vision.Image(content=content)

crop_hints_params = vision.CropHintsParams(aspect_ratios=[1.77])
image_context = vision.ImageContext(crop_hints_params=crop_hints_params)

response = client.crop_hints(image=image, image_context=image_context)
hints = response.crop_hints_annotation.crop_hints

for n, hint in enumerate(hints):
    print(f"\nCrop Hint: {n}")

    vertices = [
        f"({vertex.x},{vertex.y})" for vertex in hint.bounding_poly.vertices
    ]

    print("bounds: {}".format(",".join(vertices)))

if response.error.message:
    raise Exception(
        "{}\nFor more info on error messages, check: "
        "https://cloud.google.com/apis/design/errors".format(response.error.message)
    )

请注意，宽高比需要通过 CropHintsParams 和 ImageContext 传入。