Python Streamlit st.cache用法及代码示例

@st.cache
 def fetch_and_clean_data(url):
     # Fetch data from URL here, and then clean it up.
     return data

d1 = fetch_and_clean_data(DATA_URL_1)
# Actually executes the function, since this is the first time it was
# encountered.

d2 = fetch_and_clean_data(DATA_URL_1)
# Does not execute the function. Instead, returns its previously computed
# value. This means that now the data in d1 is the same as in d2.

d3 = fetch_and_clean_data(DATA_URL_2)
# This is a different URL, so the function executes.

设置坚持参数，使用该命令如下：

@st.cache(persist=True)
 def fetch_and_clean_data(url):
     # Fetch data from URL here, and then clean it up.
     return data

要禁用散列返回值，请设置allow_output_mutation参数为True：

@st.cache(allow_output_mutation=True)
 def fetch_and_clean_data(url):
     # Fetch data from URL here, and then clean it up.
     return data

要覆盖默认散列行为，请传递自定义散列函数。您可以通过映射类型来做到这一点(例如MongoClient) 到哈希函数 (ID) 像这样：

@st.cache(hash_funcs={MongoClient: id})
 def connect_to_database(url):
     return MongoClient(url)

或者，您可以映射类型的完全限定名称(例如“pymongo.mongo_client.MongoClient”) 改为散列函数：

@st.cache(hash_funcs={"pymongo.mongo_client.MongoClient": id})
 def connect_to_database(url):
     return MongoClient(url)