Python Streamlit st.cache用法及代碼示例

@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.

設置堅持參數，使用該命令如下：

@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，請設置allow_output_mutation參數為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

要覆蓋默認散列行為，請傳遞自定義散列函數。您可以通過映射類型來做到這一點(例如MongoClient) 到哈希函數 (ID) 像這樣：

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

或者，您可以映射類型的完全限定名稱(例如“pymongo.mongo_client.MongoClient”) 改為散列函數：

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