使用Python的ShopifyAPI添加商品元字段遇问题：返回metafield(None)

我用Shopify API创建商品没问题，但执行product.save()后添加元字段时遇到困难。商品能在Shopify后台显示，但元字段返回metafield(None)。我的代码如下：

import shopify
# Configure store details
shop_url = 'store.myshopify.com'
admin_api_key = 'shpat_'
api_version = '2022-07'

# Create and activate a new session
session = shopify.Session(shop_url, api_version, admin_api_key)
shopify.ShopifyResource.activate_session(session)

# Create a new product Object, set the title
product = shopify.Product()
product.handle = "new-product"
product.title = "New product"
product.body_html = "Test description"
product.product_type = "Type"
product.vendor = "Vendor"
product.product_type = "Category"
product.tags = "Tag"
product.price = "9.99"
product.weight = "1.0"
product.weight_unit = 'kg'

variant = shopify.Variant({'sku': 'P1', 'price': 9.99, 'requires_shipping': True})
product.variants = [variant]

# Save the product object to Shopify
product.save()

# Add the metafield to the saved product object "product.metafields.custom.maker"
product.add_metafield(shopify.Metafield({
    'namespace':"custom",
    'key':"maker",
    'value':"Maker",
    'type':"string"
}))

# Save the updated product object to Shopify
product.save()

问题原因 #

直接在已保存的product对象上调用add_metafield后再执行save()，这种方式在Shopify Python API中无法确保元字段正确同步到服务器——元字段属于独立的API资源，不能通过修改商品对象的方式间接保存。另外代码中product.price的设置是无效的，商品价格只能通过Variant对象配置。

解决方案 #

有两种可靠的实现方式：

方式一：创建商品时直接包含元字段 #

初始化Product对象时就嵌入元字段，一次性完成保存操作：

import shopify
# 配置商店信息
shop_url = 'store.myshopify.com'
admin_api_key = 'shpat_'
api_version = '2022-07'

# 创建并激活会话
session = shopify.Session(shop_url, api_version, admin_api_key)
shopify.ShopifyResource.activate_session(session)

# 初始化商品并设置属性
product = shopify.Product()
product.handle = "new-product"
product.title = "New product"
product.body_html = "Test description"
product.product_type = "Category"
product.vendor = "Vendor"
product.tags = "Tag"
product.weight = "1.0"
product.weight_unit = 'kg'

# 创建商品变体
variant = shopify.Variant({'sku': 'P1', 'price': 9.99, 'requires_shipping': True})
product.variants = [variant]

# 直接添加元字段到商品对象
metafield = shopify.Metafield({
    'namespace':"custom",
    'key':"maker",
    'value':"Maker",
    'type':"string"
})
product.metafields = [metafield]

# 一次性保存商品及关联元字段
product.save()

方式二：单独创建元字段并关联已保存商品 #

如果必须先保存商品再添加元字段，需单独创建Metafield对象并指定关联的商品ID：

import shopify
# 配置商店信息
shop_url = 'store.myshopify.com'
admin_api_key = 'shpat_'
api_version = '2022-07'

# 创建并激活会话
session = shopify.Session(shop_url, api_version, admin_api_key)
shopify.ShopifyResource.activate_session(session)

# 创建并保存商品
product = shopify.Product()
product.handle = "new-product"
product.title = "New product"
product.body_html = "Test description"
product.product_type = "Category"
product.vendor = "Vendor"
product.tags = "Tag"
product.weight = "1.0"
product.weight_unit = 'kg'

variant = shopify.Variant({'sku': 'P1', 'price': 9.99, 'requires_shipping': True})
product.variants = [variant]

product.save()

# 单独创建元字段并关联到目标商品
metafield = shopify.Metafield({
    'namespace':"custom",
    'key':"maker",
    'value':"Maker",
    'type':"string",
    'owner_resource': 'product',
    'owner_id': product.id
})
metafield.save()

内容的提问来源于stack exchange，提问作者Logan S